diff --git a/appinfo/routes.php b/appinfo/routes.php
index 685a6b8756..7e9aadc5d2 100644
--- a/appinfo/routes.php
+++ b/appinfo/routes.php
@@ -57,6 +57,8 @@
 		['name' => 'card#removeLabel', 'url' => '/cards/{cardId}/label/{labelId}', 'verb' => 'DELETE'],
 		['name' => 'card#assignUser', 'url' => '/cards/{cardId}/assign', 'verb' => 'POST'],
 		['name' => 'card#unassignUser', 'url' => '/cards/{cardId}/unassign', 'verb' => 'PUT'],
+		['name' => 'card#assignDependentCard', 'url' => '/cards/{cardId}/dependentCards/{dependentCardId}', 'verb' => 'POST'],
+		['name' => 'card#removeDependentCard', 'url' => '/cards/{cardId}/dependentCards/{dependentCardId}', 'verb' => 'DELETE'],
 
 		// attachments
 		['name' => 'attachment#getAll', 'url' => '/cards/{cardId}/attachments', 'verb' => 'GET'],
@@ -105,6 +107,8 @@
 		['name' => 'card_api#assignUser', 'url' => '/api/v{apiVersion}/boards/{boardId}/stacks/{stackId}/cards/{cardId}/assignUser', 'verb' => 'PUT'],
 		['name' => 'card_api#unassignUser', 'url' => '/api/v{apiVersion}/boards/{boardId}/stacks/{stackId}/cards/{cardId}/unassignUser', 'verb' => 'PUT'],
 		['name' => 'card_api#reorder', 'url' => '/api/v{apiVersion}/boards/{boardId}/stacks/{stackId}/cards/{cardId}/reorder', 'verb' => 'PUT'],
+		['name' => 'card_api#assignDependentCard', 'url' => '/api/v{apiVersion}/boards/{boardId}/stacks/{stackId}/cards/{cardId}/dependentCards/{dependentCardId}', 'verb' => 'POST'],
+		['name' => 'card_api#removeDependentCard', 'url' => '/api/v{apiVersion}/boards/{boardId}/stacks/{stackId}/cards/{cardId}/dependentCards/{dependentCardId}', 'verb' => 'DELETE'],
 		['name' => 'card_api#archive', 'url' => '/api/v{apiVersion}/boards/{boardId}/stacks/{stackId}/cards/{cardId}/archive', 'verb' => 'PUT'],
 		['name' => 'card_api#unarchive', 'url' => '/api/v{apiVersion}/boards/{boardId}/stacks/{stackId}/cards/{cardId}/unarchive', 'verb' => 'PUT'],
 		['name' => 'card_api#delete', 'url' => '/api/v{apiVersion}/boards/{boardId}/stacks/{stackId}/cards/{cardId}', 'verb' => 'DELETE'],
@@ -146,6 +150,8 @@
 		['name' => 'card_ocs#unAssignUser', 'url' => '/api/v{apiVersion}/cards/{cardId}/unassign', 'verb' => 'PUT'],
 		['name' => 'card_ocs#removeLabel', 'url' => '/api/v{apiVersion}/cards/{cardId}/label/{labelId}', 'verb' => 'DELETE'],
 		['name' => 'card_ocs#reorder', 'url' => '/api/v{apiVersion}/cards/{cardId}/reorder', 'verb' => 'PUT'],
+		['name' => 'card_ocs#assignDependentCard', 'url' => '/api/v{apiVersion}/cards/{cardId}/dependentCards/{dependentCardId}', 'verb' => 'POST'],
+		['name' => 'card_ocs#removeDependentCard', 'url' => '/api/v{apiVersion}/cards/{cardId}/dependentCards/{dependentCardId}', 'verb' => 'DELETE'],
 
 		['name' => 'stack_ocs#create', 'url' => '/api/v{apiVersion}/stacks', 'verb' => 'POST'],
 		['name' => 'stack_ocs#setDoneStack', 'url' => '/api/v{apiVersion}/stacks/{stackId}/done', 'verb' => 'PUT'],
diff --git a/cypress/e2e/cardFeatures.js b/cypress/e2e/cardFeatures.js
index fbc08fa9b7..7fa97d846c 100644
--- a/cypress/e2e/cardFeatures.js
+++ b/cypress/e2e/cardFeatures.js
@@ -205,10 +205,14 @@ describe('Card', function () {
 
 			cy.reload()
 			cy.get('.modal__card').should('be.visible')
+
+			// Scroll to the bottom to ensure all content is loaded and visible
+			cy.get('.modal__card .app-sidebar-tabs, .modal__card .app-sidebar__tab--active').first().scrollTo('bottom', { ensureScrollable: false })
+			cy.contains('.modal__card .ProseMirror p', 'Paragraph').scrollIntoView().should('be.visible')
+
 			cy.get('.modal__card .ProseMirror h1').contains('Hello world writing more text').should('be.visible')
 			cy.get('.modal__card .ProseMirror li').eq(0).contains('List item').should('be.visible')
 			cy.get('.modal__card .ProseMirror li').eq(1).contains('with entries').should('be.visible')
-			cy.get('.modal__card .ProseMirror p').contains('Paragraph').should('be.visible')
 		})
 
 		it('Smart picker', () => {
diff --git a/lib/Controller/CardApiController.php b/lib/Controller/CardApiController.php
index 87f22dbfda..4bd3fdd2cb 100644
--- a/lib/Controller/CardApiController.php
+++ b/lib/Controller/CardApiController.php
@@ -149,6 +149,28 @@ public function unassignUser(int $cardId, string $userId, int $type = 0): DataRe
 		return new DataResponse($card, HTTP::STATUS_OK);
 	}
 
+	/**
+	 * Assign a dependent card
+	 */
+	#[NoAdminRequired]
+	#[CORS]
+	#[NoCSRFRequired]
+	public function assignDependentCard(int $cardId, int $dependentCardId): DataResponse {
+		$card = $this->cardService->assignDependentCard($cardId, $dependentCardId);
+		return new DataResponse($card, HTTP::STATUS_OK);
+	}
+
+	/**
+	 * Remove a dependent card
+	 */
+	#[NoAdminRequired]
+	#[CORS]
+	#[NoCSRFRequired]
+	public function removeDependentCard(int $cardId, int $dependentCardId): DataResponse {
+		$card = $this->cardService->removeDependentCard($cardId, $dependentCardId);
+		return new DataResponse($card, HTTP::STATUS_OK);
+	}
+
 	/**
 	 * Archive card
 	 */
diff --git a/lib/Controller/CardController.php b/lib/Controller/CardController.php
index b8c80456d9..58e412665d 100644
--- a/lib/Controller/CardController.php
+++ b/lib/Controller/CardController.php
@@ -128,4 +128,14 @@ public function assignUser(int $cardId, string $userId, int $type = 0): Assignme
 	public function unassignUser(int $cardId, string $userId, int $type = 0): Assignment {
 		return $this->assignmentService->unassignUser($cardId, $userId, $type);
 	}
+
+	#[NoAdminRequired]
+	public function assignDependentCard(int $cardId, int $dependentCardId): Card {
+		return $this->cardService->assignDependentCard($cardId, $dependentCardId);
+	}
+
+	#[NoAdminRequired]
+	public function removeDependentCard(int $cardId, int $dependentCardId): Card {
+		return $this->cardService->removeDependentCard($cardId, $dependentCardId);
+	}
 }
diff --git a/lib/Controller/CardOcsController.php b/lib/Controller/CardOcsController.php
index 6805e6bd6e..2ea2a98256 100644
--- a/lib/Controller/CardOcsController.php
+++ b/lib/Controller/CardOcsController.php
@@ -8,6 +8,7 @@
 namespace OCA\Deck\Controller;
 
 use OCA\Deck\Model\OptionalNullableValue;
+use OCA\Deck\NotImplementedException;
 use OCA\Deck\Service\AssignmentService;
 use OCA\Deck\Service\BoardService;
 use OCA\Deck\Service\CardService;
@@ -170,4 +171,28 @@ public function reorder(int $cardId, int $stackId, int $order, ?int $boardId): D
 		}
 		return new DataResponse($this->cardService->reorder($cardId, $stackId, $order));
 	}
+
+	#[NoAdminRequired]
+	#[PublicPage]
+	public function assignDependentCard(int $cardId, int $dependentCardId, ?int $boardId = null): DataResponse {
+		if ($boardId) {
+			$board = $this->boardService->find($boardId, false);
+			if ($board->getExternalId()) {
+				throw new NotImplementedException('Dependent cards are not supported for external boards');
+			}
+		}
+		return new DataResponse($this->cardService->assignDependentCard($cardId, $dependentCardId));
+	}
+
+	#[NoAdminRequired]
+	#[PublicPage]
+	public function removeDependentCard(int $cardId, int $dependentCardId, ?int $boardId = null): DataResponse {
+		if ($boardId) {
+			$board = $this->boardService->find($boardId, false);
+			if ($board->getExternalId()) {
+				throw new NotImplementedException('Dependent cards are not supported for external boards');
+			}
+		}
+		return new DataResponse($this->cardService->removeDependentCard($cardId, $dependentCardId));
+	}
 }
diff --git a/lib/Db/Card.php b/lib/Db/Card.php
index ad8e7f67d9..c30e771307 100644
--- a/lib/Db/Card.php
+++ b/lib/Db/Card.php
@@ -37,6 +37,9 @@
  * @method ?DateTime getStartdate()
  * @method void setStartdate(?DateTime $startdate)
  *
+ * @method void setDependentCards(array $cardIds)
+ * @method null|array getDependentCards()
+ *
  * @method void setLabels(Label[] $labels)
  * @method null|Label[] getLabels()
  *
@@ -90,6 +93,7 @@ class Card extends RelationalEntity {
 	protected $deletedAt = 0;
 	protected $commentsUnread = 0;
 	protected $commentsCount = 0;
+	protected ?array $dependentCards = null;
 
 	protected $relatedStack = null;
 	protected $relatedBoard = null;
@@ -113,6 +117,7 @@ public function __construct() {
 		$this->addType('deletedAt', 'integer');
 		$this->addType('duedate', 'datetime');
 		$this->addType('startdate', 'datetime');
+		$this->addRelation('dependentCards');
 		$this->addRelation('labels');
 		$this->addRelation('assignedUsers');
 		$this->addRelation('attachments');
diff --git a/lib/Db/CardMapper.php b/lib/Db/CardMapper.php
index 761c9cfad4..67db013b57 100644
--- a/lib/Db/CardMapper.php
+++ b/lib/Db/CardMapper.php
@@ -614,6 +614,7 @@ public function searchRaw($boardIds, $term, $limit = null, $offset = null) {
 
 	public function delete(Entity $entity): Entity {
 		$this->labelMapper->deleteLabelAssignmentsForCard($entity->getId());
+		$this->removeDependenciesForCard($entity->getId());
 		$this->cache->remove('findBoardId:' . $entity->getId());
 		return parent::delete($entity);
 	}
@@ -643,6 +644,76 @@ public function removeLabel(int $card, int $label): void {
 		$qb->executeStatement();
 	}
 
+	/**
+	 * @param int[] $cardIds
+	 * @return array<int, int[]>
+	 */
+	public function findDependenciesForCards(array $cardIds): array {
+		if ($cardIds === []) {
+			return [];
+		}
+
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('card_id', 'dependent_card_id')
+			->from('deck_dependent_cards')
+			->where($qb->expr()->in('card_id', $qb->createNamedParameter($cardIds, IQueryBuilder::PARAM_INT_ARRAY)))
+			->orderBy('card_id')
+			->addOrderBy('dependent_card_id');
+
+		$result = [];
+		$queryResult = $qb->executeQuery();
+		while ($row = $queryResult->fetch()) {
+			$cardId = (int)$row['card_id'];
+			$result[$cardId][] = (int)$row['dependent_card_id'];
+		}
+
+		return $result;
+	}
+
+	public function addDependency(int $cardId, int $dependentCardId): bool {
+		if ($this->hasDependency($cardId, $dependentCardId)) {
+			return false;
+		}
+
+		$qb = $this->db->getQueryBuilder();
+		$qb->insert('deck_dependent_cards')
+			->values([
+				'card_id' => $qb->createNamedParameter($cardId, IQueryBuilder::PARAM_INT),
+				'dependent_card_id' => $qb->createNamedParameter($dependentCardId, IQueryBuilder::PARAM_INT),
+			]);
+		$qb->executeStatement();
+
+		return true;
+	}
+
+	public function removeDependency(int $cardId, int $dependentCardId): bool {
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete('deck_dependent_cards')
+			->where($qb->expr()->eq('card_id', $qb->createNamedParameter($cardId, IQueryBuilder::PARAM_INT)))
+			->andWhere($qb->expr()->eq('dependent_card_id', $qb->createNamedParameter($dependentCardId, IQueryBuilder::PARAM_INT)));
+
+		return $qb->executeStatement() > 0;
+	}
+
+	public function removeDependenciesForCard(int $cardId): void {
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete('deck_dependent_cards')
+			->where($qb->expr()->eq('card_id', $qb->createNamedParameter($cardId, IQueryBuilder::PARAM_INT)))
+			->orWhere($qb->expr()->eq('dependent_card_id', $qb->createNamedParameter($cardId, IQueryBuilder::PARAM_INT)));
+		$qb->executeStatement();
+	}
+
+	private function hasDependency(int $cardId, int $dependentCardId): bool {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('id')
+			->from('deck_dependent_cards')
+			->where($qb->expr()->eq('card_id', $qb->createNamedParameter($cardId, IQueryBuilder::PARAM_INT)))
+			->andWhere($qb->expr()->eq('dependent_card_id', $qb->createNamedParameter($dependentCardId, IQueryBuilder::PARAM_INT)))
+			->setMaxResults(1);
+
+		return $qb->executeQuery()->fetchOne() !== false;
+	}
+
 	public function isOwner(string $userId, int $id): bool {
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('c.id')
diff --git a/lib/Migration/Version11002Date20260410000000.php b/lib/Migration/Version11002Date20260410000000.php
new file mode 100644
index 0000000000..befe95202c
--- /dev/null
+++ b/lib/Migration/Version11002Date20260410000000.php
@@ -0,0 +1,43 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+namespace OCA\Deck\Migration;
+
+use Closure;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+class Version11002Date20260410000000 extends SimpleMigrationStep {
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options) {
+		$schema = $schemaClosure();
+
+		if (!$schema->hasTable('deck_dependent_cards')) {
+			$table = $schema->createTable('deck_dependent_cards');
+			$table->addColumn('id', 'integer', [
+				'autoincrement' => true,
+				'notnull' => true,
+				'length' => 4,
+			]);
+			$table->addColumn('card_id', 'integer', [
+				'notnull' => true,
+				'length' => 4,
+				'default' => 0,
+			]);
+			$table->addColumn('dependent_card_id', 'integer', [
+				'notnull' => true,
+				'length' => 4,
+				'default' => 0,
+			]);
+			$table->setPrimaryKey(['id']);
+			$table->addUniqueIndex(['card_id', 'dependent_card_id'], 'deck_depend_cards_uidx');
+			$table->addIndex(['card_id'], 'deck_depend_cards_idx_c');
+			$table->addIndex(['dependent_card_id'], 'deck_depend_cards_idx_d');
+		}
+		return $schema;
+	}
+}
diff --git a/lib/Service/CardService.php b/lib/Service/CardService.php
index 877d212c5b..3b12d2a891 100644
--- a/lib/Service/CardService.php
+++ b/lib/Service/CardService.php
@@ -100,6 +100,7 @@ public function enrichCards(array $cards): array {
 
 		$assignedLabels = $this->labelMapper->findAssignedLabelsForCards($cardIds);
 		$assignedUsers = $this->assignedUsersMapper->findIn($cardIds);
+		$dependenciesByCard = $this->cardMapper->findDependenciesForCards($cardIds);
 
 		// Pre-group labels and users by card ID
 		$labelsByCard = [];
@@ -114,6 +115,7 @@ public function enrichCards(array $cards): array {
 		foreach ($cards as $card) {
 			$card->setLabels($labelsByCard[$card->getId()] ?? []);
 			$card->setAssignedUsers($usersByCard[$card->getId()] ?? []);
+			$card->setDependentCards($dependenciesByCard[$card->getId()] ?? []);
 		}
 
 		return array_map(
@@ -675,4 +677,62 @@ public function getCardUrl(int $cardId): string {
 	public function getRedirectUrlForCard(int $cardId): string {
 		return $this->urlGenerator->linkToRouteAbsolute('deck.page.redirectToCard', ['cardId' => $cardId]);
 	}
+
+	/**
+	 * @throws StatusException
+	 * @throws \OCA\Deck\NoPermissionException
+	 * @throws \OCP\AppFramework\Db\DoesNotExistException
+	 * @throws \OCP\AppFramework\Db\MultipleObjectsReturnedException
+	 * @throws BadRequestException
+	 */
+	public function assignDependentCard(int $cardId, int $dependentCardId): Card {
+		$this->permissionService->checkPermission($this->cardMapper, $cardId, Acl::PERMISSION_EDIT);
+		$this->permissionService->checkPermission($this->cardMapper, $dependentCardId, Acl::PERMISSION_READ);
+
+		if ($this->boardService->isArchived($this->cardMapper, $cardId)) {
+			throw new StatusException('Operation not allowed. This board is archived.');
+		}
+
+		$card = $this->cardMapper->find($cardId);
+		if ($card->getArchived()) {
+			throw new StatusException('Operation not allowed. This card is archived.');
+		}
+
+		if ($this->cardMapper->addDependency($cardId, $dependentCardId)) {
+			$this->changeHelper->cardChanged($cardId);
+			$this->activityManager->triggerEvent(ActivityManager::DECK_OBJECT_CARD, $card, ActivityManager::SUBJECT_CARD_UPDATE);
+		}
+
+		[$card] = $this->enrichCards([$card]);
+		return $card;
+	}
+
+	/**
+	 * @throws StatusException
+	 * @throws \OCA\Deck\NoPermissionException
+	 * @throws \OCP\AppFramework\Db\DoesNotExistException
+	 * @throws \OCP\AppFramework\Db\MultipleObjectsReturnedException
+	 * @throws BadRequestException
+	 */
+	public function removeDependentCard(int $cardId, int $dependentCardId): Card {
+		$this->permissionService->checkPermission($this->cardMapper, $cardId, Acl::PERMISSION_EDIT);
+		$this->permissionService->checkPermission($this->cardMapper, $dependentCardId, Acl::PERMISSION_READ);
+
+		if ($this->boardService->isArchived($this->cardMapper, $cardId)) {
+			throw new StatusException('Operation not allowed. This board is archived.');
+		}
+
+		$card = $this->cardMapper->find($cardId);
+		if ($card->getArchived()) {
+			throw new StatusException('Operation not allowed. This card is archived.');
+		}
+
+		if ($this->cardMapper->removeDependency($cardId, $dependentCardId)) {
+			$this->changeHelper->cardChanged($cardId);
+			$this->activityManager->triggerEvent(ActivityManager::DECK_OBJECT_CARD, $card, ActivityManager::SUBJECT_CARD_UPDATE);
+		}
+
+		[$card] = $this->enrichCards([$card]);
+		return $card;
+	}
 }
diff --git a/src/components/card/CardSidebarTabDetails.vue b/src/components/card/CardSidebarTabDetails.vue
index 3c1d6ec770..c70ebdf077 100644
--- a/src/components/card/CardSidebarTabDetails.vue
+++ b/src/components/card/CardSidebarTabDetails.vue
@@ -28,6 +28,11 @@
 			@change="updateCardDue"
 			@input="debouncedUpdateCardDue" />
 
+		<DependentCardsSelector :card="card"
+			:can-edit="canEdit"
+			@select="assignDependentCard"
+			@remove="removeDependentCard" />
+
 		<div v-if="projectsEnabled" class="section-wrapper">
 			<NcCollectionList v-if="card.id"
 				:id="`${card.id}`"
@@ -59,10 +64,12 @@ import AssignmentSelector from './AssignmentSelector.vue'
 import DueDateSelector from './DueDateSelector.vue'
 import StartDateSelector from './StartDateSelector.vue'
 import { debounce } from 'lodash'
+import DependentCardsSelector from './DependentCardsSelector.vue'
 
 export default {
 	name: 'CardSidebarTabDetails',
 	components: {
+		DependentCardsSelector,
 		DueDateSelector,
 		StartDateSelector,
 		AssignmentSelector,
@@ -203,6 +210,39 @@ export default {
 			}
 			this.$store.dispatch('removeLabel', data)
 		},
+		assignDependentCard(dependentCard) {
+			if (!dependentCard?.id) {
+				return
+			}
+
+			if (!Array.isArray(this.copiedCard.dependentCards)) {
+				this.copiedCard.dependentCards = []
+			}
+
+			if (!this.copiedCard.dependentCards.includes(dependentCard.id)) {
+				this.copiedCard.dependentCards.push(dependentCard.id)
+			}
+
+			this.$store.dispatch('assignDependentCard', {
+				card: this.copiedCard,
+				dependentCard,
+			})
+		},
+		removeDependentCard(dependentCard) {
+			const dependentCardId = dependentCard?.id
+			if (!dependentCardId) {
+				return
+			}
+
+			if (Array.isArray(this.copiedCard.dependentCards)) {
+				this.copiedCard.dependentCards = this.copiedCard.dependentCards.filter((id) => id !== dependentCardId)
+			}
+
+			this.$store.dispatch('removeDependentCard', {
+				card: this.copiedCard,
+				dependentCardId,
+			})
+		},
 		stringify(date) {
 			return moment(date).locale(this.locale).format('LLL')
 		},
diff --git a/src/components/card/DependentCardsSelector.vue b/src/components/card/DependentCardsSelector.vue
new file mode 100644
index 0000000000..797cfcd520
--- /dev/null
+++ b/src/components/card/DependentCardsSelector.vue
@@ -0,0 +1,263 @@
+<!--
+  - SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+  - SPDX-License-Identifier: AGPL-3.0-or-later
+-->
+<template>
+	<CardDetailEntry :label="t('deck', 'Assign dependent cards')" data-test="dependant-cards-selector">
+		<template #icon>
+			<ListBoxOutline :size="20" />
+		</template>
+		<div class="selector-wrapper--selector">
+			<ul v-if="selectedDependentCards.length > 0" class="dependency-list">
+				<li v-for="dependentCard in selectedDependentCards" :key="dependentCard.id" class="dependency-item">
+					<NcButton v-if="isEditable && !dependentCard.done"
+						type="button"
+						:aria-label="t('deck', 'Mark as done')"
+						:title="t('deck', 'Mark as done')"
+						@click.stop="changeCardDoneStatus(dependentCard)">
+						<template #icon>
+							<CircleOutline :size="16" />
+						</template>
+					</NcButton>
+					<NcButton v-if="isEditable && dependentCard.done"
+						type="button"
+						:aria-label="t('deck', 'Mark as not done')"
+						:title="t('deck', 'Mark as not done')"
+						@click.stop="changeCardDoneStatus(dependentCard)">
+						<template #icon>
+							<CheckCircle :size="16" class="done-indicator" />
+						</template>
+					</NcButton>
+					<div class="dependency-link" @click.stop="openCard(dependentCard)">
+						<span :class="{ 'dependency-title--done': !!dependentCard.done }">{{ dependentCard.title }}</span>
+					</div>
+					<NcButton v-if="isEditable"
+						type="button"
+						variant="tertiary"
+						:aria-label="t('deck', 'Remove dependency')"
+						:title="t('deck', 'Remove dependency')"
+						@click.stop="onRemove(dependentCard)">
+						<template #icon>
+							<Close :size="20" />
+						</template>
+					</NcButton>
+				</li>
+			</ul>
+
+			<NcButton v-if="isEditable && !showSelector"
+				class="add-dependency-button"
+				type="button"
+				variant="tertiary"
+				:aria-label="t('deck', 'Add dependent card')"
+				@click="openSelector">
+				<template #icon>
+					<Plus :size="20" />
+				</template>
+				{{ t('deck', 'Add dependent card') }}
+			</NcButton>
+
+			<div v-if="isEditable && showSelector" class="selector-row">
+				<NcSelect ref="cardSelector"
+					:options="candidateCards"
+					:multiple="true"
+					:close-on-select="true"
+					:aria-label-combobox="t('deck', 'Assign a dependent card…')"
+					:placeholder="t('deck', 'Select a dependent card…')"
+					label="title"
+					track-by="id"
+					@option:selected="onSelect">
+					<template #option="scope">
+						<div class="dependency-option">
+							<span>{{ scope.title }}</span>
+						</div>
+					</template>
+				</NcSelect>
+				<NcButton type="button"
+					variant="tertiary"
+					:aria-label="t('deck', 'Cancel')"
+					:title="t('deck', 'Cancel')"
+					@click="showSelector = false">
+					<template #icon>
+						<Close :size="20" />
+					</template>
+				</NcButton>
+			</div>
+		</div>
+	</CardDetailEntry>
+</template>
+
+<script>
+import { defineComponent } from 'vue'
+import { mapGetters, mapState } from 'vuex'
+import { generateUrl } from '@nextcloud/router'
+import { NcSelect, NcButton } from '@nextcloud/vue'
+import ListBoxOutline from 'vue-material-design-icons/ListBoxOutline.vue'
+import CircleOutline from 'vue-material-design-icons/CircleOutline.vue'
+import CheckCircle from 'vue-material-design-icons/CheckCircle.vue'
+import Close from 'vue-material-design-icons/Close.vue'
+import Plus from 'vue-material-design-icons/Plus.vue'
+import CardDetailEntry from './CardDetailEntry.vue'
+
+export default defineComponent({
+	name: 'DependentCardsSelector',
+	components: {
+		CardDetailEntry,
+		ListBoxOutline,
+		CircleOutline,
+		CheckCircle,
+		Close,
+		Plus,
+		NcSelect,
+		NcButton,
+	},
+	props: {
+		card: {
+			type: Object,
+			default: null,
+		},
+		canEdit: {
+			type: Boolean,
+			default: false,
+		},
+	},
+	data() {
+		return {
+			showSelector: false,
+		}
+	},
+	computed: {
+		...mapState({
+			cards: state => state.card.cards,
+		}),
+		...mapGetters(['cardById', 'stackById']),
+		isEditable() {
+			return this.canEdit && !this.card?.done && !this.card?.archived
+		},
+		dependentCardIds() {
+			if (!Array.isArray(this.card?.dependentCards)) {
+				return []
+			}
+			return this.card.dependentCards
+				.map((id) => parseInt(id, 10))
+				.filter((id) => Number.isInteger(id))
+		},
+		selectedDependentCards() {
+			return this.dependentCardIds
+				.map((id) => this.cardById(id))
+				.filter(Boolean)
+		},
+		candidateCards() {
+			const currentBoardId = this.getCardBoardId(this.card)
+			return this.cards
+				.filter((candidate) => candidate.id !== this.card?.id)
+				.filter((candidate) => !this.dependentCardIds.includes(candidate.id))
+				.filter((candidate) => this.getCardBoardId(candidate) === currentBoardId)
+				.sort((a, b) => a.order - b.order || a.createdAt - b.createdAt)
+		},
+	},
+	methods: {
+		openSelector() {
+			this.showSelector = true
+			this.$nextTick(() => {
+				this.$refs.cardSelector?.$el?.querySelector('input')?.focus()
+			})
+		},
+		onSelect(options) {
+			const addedCard = options.find((option) => !this.dependentCardIds.includes(option.id))
+			if (addedCard) {
+				this.$emit('select', addedCard)
+				this.showSelector = false
+			}
+		},
+		onRemove(removedCard) {
+			this.$emit('remove', removedCard)
+		},
+		getCardBoardId(card) {
+			if (!card) {
+				return null
+			}
+
+			if (card.boardId) {
+				return card.boardId
+			}
+
+			const stack = this.stackById(card.stackId)
+			return stack?.boardId ?? null
+		},
+		openCard(dependentCard) {
+			if (!dependentCard?.id) {
+				return
+			}
+
+			const boardId = this.getCardBoardId(dependentCard)
+				?? this.getCardBoardId(this.card)
+				?? parseInt(this.$route?.params?.id, 10)
+
+			if (!Number.isInteger(boardId)) {
+				return
+			}
+
+			if (this.$router) {
+				this.$router.push({ name: 'card', params: { id: boardId, cardId: dependentCard.id } }).catch(() => {})
+				return
+			}
+
+			window.location = generateUrl('/apps/deck') + `#/board/${boardId}/card/${dependentCard.id}`
+		},
+		changeCardDoneStatus(card) {
+			this.$store.dispatch('changeCardDoneStatus', { ...card, done: !card.done })
+		},
+	},
+})
+</script>
+<style scoped lang="scss">
+.dependency-list {
+	width: 100%;
+	margin: 0;
+	padding: 0;
+	list-style: none;
+}
+
+.dependency-item {
+	display: flex;
+	justify-content: space-between;
+	margin-bottom: 8px;
+	gap: 6px;
+}
+
+.dependency-link {
+	display: inline-flex;
+	align-items: center;
+	gap: 6px;
+	cursor: pointer;
+	border: 2px solid var(--color-border-dark);
+	box-shadow: none;
+	border-radius: var(--border-radius-large);
+	padding: calc(var(--default-grid-baseline) * 2) calc(var(--default-grid-baseline) * 2) var(--default-grid-baseline);
+	padding-top: 0;
+	padding-bottom: 0;
+	width: 100%;
+}
+
+.dependency-link:hover {
+	border-color: var(--color-main-text) !important;
+}
+
+.dependency-link span {
+	cursor: pointer;
+}
+
+.done-indicator {
+	color: var(--color-element-success, var(--color-success-text));
+}
+
+.dependency-title--done {
+	text-decoration: line-through;
+}
+
+.selector-row {
+	display: flex;
+	align-items: center;
+	gap: 6px;
+}
+</style>
diff --git a/src/services/CardApi.js b/src/services/CardApi.js
index 59cfbea387..9057a738cc 100644
--- a/src/services/CardApi.js
+++ b/src/services/CardApi.js
@@ -234,4 +234,38 @@ export class CardApi {
 			})
 	}
 
+	assignDependentCard(cardId, dependentCardId, boardId) {
+		return axios.post(this.ocsUrl(`/cards/${cardId}/dependentCards/${dependentCardId}`), { boardId: boardId ?? null })
+			.then(
+				(response) => {
+					return Promise.resolve(response.data.ocs.data)
+				},
+				(err) => {
+					return Promise.reject(err)
+				},
+			)
+			.catch((err) => {
+				return Promise.reject(err)
+			})
+	}
+
+	removeDependentCard(cardId, dependentCardId, boardId) {
+		return axios.delete(this.ocsUrl(`/cards/${cardId}/dependentCards/${dependentCardId}`), {
+			data: {
+				boardId: boardId ?? null,
+			},
+		})
+			.then(
+				(response) => {
+					return Promise.resolve(response.data.ocs.data)
+				},
+				(err) => {
+					return Promise.reject(err)
+				},
+			)
+			.catch((err) => {
+				return Promise.reject(err)
+			})
+	}
+
 }
diff --git a/src/store/card.js b/src/store/card.js
index 1028c50479..d1d3e8e043 100644
--- a/src/store/card.js
+++ b/src/store/card.js
@@ -373,6 +373,16 @@ export default function cardModuleFactory() {
 				await apiClient.removeLabelFromCard(data)
 				commit('updateCardProperty', { property: 'labels', card: data.card })
 			},
+			async assignDependentCard({ commit }, { card, dependentCard }) {
+				const boardId = this.state.currentBoard.id
+				const updatedCard = await apiClient.assignDependentCard(card.id, dependentCard.id, boardId)
+				commit('updateCardProperty', { property: 'dependentCards', card: updatedCard })
+			},
+			async removeDependentCard({ commit }, { card, dependentCardId }) {
+				const boardId = this.state.currentBoard.id
+				const updatedCard = await apiClient.removeDependentCard(card.id, dependentCardId, boardId)
+				commit('updateCardProperty', { property: 'dependentCards', card: updatedCard })
+			},
 			async updateCardDesc({ commit, getters }, card) {
 				const stack = getters.stackById(card.stackId)
 				const updatedCard = await apiClient.updateCard(card, stack.boardId)
diff --git a/tests/data/deck.json b/tests/data/deck.json
index 207de16084..0fa4514aef 100644
--- a/tests/data/deck.json
+++ b/tests/data/deck.json
@@ -108,6 +108,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "ddfd0c27e53d8db94ac5e9aaa021746e",
 							"overdue": 0,
 							"boardId": 188,
@@ -143,6 +144,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "9a8ed495f7d83f8310ae6291d6dc4624",
 							"overdue": 3,
 							"boardId": 188,
@@ -190,6 +192,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "f908c4359e9ca0703f50da2bbe967594",
 							"overdue": 0,
 							"boardId": 188,
@@ -265,6 +268,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "6b20cc46fa5d2e5f65251526b50cc130",
 							"overdue": 0,
 							"boardId": 188,
@@ -310,6 +314,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "488145982535a91d9ab47db647ecf539",
 							"overdue": 0,
 							"boardId": 188,
@@ -357,6 +362,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "b97a2b19e1cafc8f95e3f4db71097214",
 							"overdue": 0,
 							"boardId": 188,
@@ -531,6 +537,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "f0450d41827f55580554c993304c8073",
 							"overdue": 0,
 							"boardId": 189,
@@ -566,6 +573,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "f0450d41827f55580554c993304c8073",
 							"overdue": 0,
 							"boardId": 189,
@@ -601,6 +609,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "1956848c45be91fefc967ee8831ea4cf",
 							"overdue": 0,
 							"boardId": 189,
@@ -636,6 +645,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "6c315c83f146485e6b2b6fdc24ffa617",
 							"overdue": 0,
 							"boardId": 189,
@@ -683,6 +693,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "d2a8b634cdd96ab5ef48910bbbd715b1",
 							"overdue": 0,
 							"boardId": 189,
@@ -730,6 +741,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "193163d8a8acedbfaba196b1f0d65bc8",
 							"overdue": 0,
 							"boardId": 189,
@@ -765,6 +777,7 @@
 							"deletedAt": 0,
 							"commentsUnread": 0,
 							"commentsCount": 0,
+							"dependentCards": null,
 							"ETag": "193163d8a8acedbfaba196b1f0d65bc8",
 							"overdue": 0,
 							"boardId": 189,
diff --git a/tests/unit/Db/CardTest.php b/tests/unit/Db/CardTest.php
index 6e06b81017..03170f11ab 100644
--- a/tests/unit/Db/CardTest.php
+++ b/tests/unit/Db/CardTest.php
@@ -44,6 +44,7 @@ private function createCard() {
 		$card->setArchived(false);
 		$card->setDone(null);
 		$card->setColor('ffffff');
+		$card->setDependentCards([2, 3]);
 		// TODO: relation shared labels acl
 		return $card;
 	}
@@ -94,6 +95,7 @@ public function testJsonSerialize() {
 			'attachments' => [],
 			'attachmentCount' => 0,
 			'assignedUsers' => null,
+			'dependentCards' => [2, 3],
 			'deletedAt' => 0,
 			'commentsUnread' => 0,
 			'commentsCount' => 0,
@@ -125,6 +127,7 @@ public function testJsonSerializeLabels() {
 			'attachments' => [],
 			'attachmentCount' => 0,
 			'assignedUsers' => null,
+			'dependentCards' => [2, 3],
 			'deletedAt' => 0,
 			'commentsUnread' => 0,
 			'commentsCount' => 0,
@@ -158,6 +161,7 @@ public function testJsonSerializeAsignedUsers() {
 			'attachments' => [],
 			'attachmentCount' => 0,
 			'assignedUsers' => ['user1'],
+			'dependentCards' => [2, 3],
 			'deletedAt' => 0,
 			'commentsUnread' => 0,
 			'commentsCount' => 0,
diff --git a/tests/unit/Service/CardServiceTest.php b/tests/unit/Service/CardServiceTest.php
index b6299b17ac..840cdd6fc1 100644
--- a/tests/unit/Service/CardServiceTest.php
+++ b/tests/unit/Service/CardServiceTest.php
@@ -207,6 +207,7 @@ public function testFind() {
 		$cardExpected->setRelatedBoard($boardMock);
 		$cardExpected->setRelatedStack($stackMock);
 		$cardExpected->setLabels([]);
+		$cardExpected->setDependentCards([]);
 		$expected = new CardDetails($cardExpected);
 
 		$actual = $this->cardService->find(123);
@@ -633,4 +634,46 @@ public function testDoneDoesNotMoveCardAlreadyInDoneColumn(): void {
 		$this->assertNotNull($result->getDone());
 		$this->assertEquals(20, $result->getStackId());
 	}
+
+	public function testAssignDependentCard() {
+		$card = Card::fromParams([
+			'id' => 42,
+			'title' => 'Card title',
+			'stackId' => 234,
+		]);
+		$stack = Stack::fromParams([
+			'id' => 234,
+			'boardId' => 1337,
+		]);
+		$this->cardMapper->expects($this->once())->method('find')->willReturn($card);
+		$this->cardMapper->expects($this->once())->method('addDependency')->with(42, 43)->willReturn(true);
+		$this->cardMapper->expects($this->once())->method('findDependenciesForCards')->with([42])->willReturn([42 => [44, 43]]);
+		$this->stackMapper->expects($this->once())
+			->method('find')
+			->with(234)
+			->willReturn($stack);
+		$result = $this->cardService->assignDependentCard(42, 43);
+		$this->assertEquals([44, 43], $result->getDependentCards());
+	}
+
+	public function testRemoveDependentCard() {
+		$card = Card::fromParams([
+			'id' => 42,
+			'title' => 'Card title',
+			'stackId' => 234,
+		]);
+		$stack = Stack::fromParams([
+			'id' => 234,
+			'boardId' => 1337,
+		]);
+		$this->cardMapper->expects($this->once())->method('find')->willReturn($card);
+		$this->cardMapper->expects($this->once())->method('removeDependency')->with(42, 43)->willReturn(true);
+		$this->cardMapper->expects($this->once())->method('findDependenciesForCards')->with([42])->willReturn([42 => [44]]);
+		$this->stackMapper->expects($this->once())
+			->method('find')
+			->with(234)
+			->willReturn($stack);
+		$result = $this->cardService->removeDependentCard(42, 43);
+		$this->assertEquals([44], $result->getDependentCards());
+	}
 }