diff --git a/server/src/repositories/tag.repository.ts b/server/src/repositories/tag.repository.ts
index d4572886af..79a46d1834 100644
--- a/server/src/repositories/tag.repository.ts
+++ b/server/src/repositories/tag.repository.ts
@@ -88,6 +88,28 @@ export class TagRepository {
     await this.db.deleteFrom('tag').where('id', '=', id).execute();
   }
 
+  @GenerateSql({ params: [DummyValue.UUID] })
+  async getAssetIdsForTag(tagId: string): Promise<string[]> {
+    const results = await this.db
+      .selectFrom('tag_asset')
+      .select(['assetId'])
+      .where('tagId', '=', tagId)
+      .execute();
+
+    return results.map(({ assetId }) => assetId);
+  }
+
+  @GenerateSql({ params: [DummyValue.UUID] })
+  async getDescendantTagIds(tagId: string): Promise<string[]> {
+    const results = await this.db
+      .selectFrom('tag_closure')
+      .select(['id_descendant'])
+      .where('id_ancestor', '=', tagId)
+      .execute();
+
+    return results.map(({ id_descendant }) => id_descendant);
+  }
+
   @ChunkedSet({ paramIndex: 1 })
   @GenerateSql({ params: [DummyValue.UUID, [DummyValue.UUID]] })
   async getAssetIds(tagId: string, assetIds: string[]): Promise<Set<string>> {
diff --git a/server/src/services/tag.service.spec.ts b/server/src/services/tag.service.spec.ts
index 6bb92abd8c..cbc9f704a5 100644
--- a/server/src/services/tag.service.spec.ts
+++ b/server/src/services/tag.service.spec.ts
@@ -169,12 +169,53 @@ describe(TagService.name, () => {
       expect(mocks.tag.delete).not.toHaveBeenCalled();
     });
 
-    it('should remove a tag', async () => {
-      mocks.tag.get.mockResolvedValue(tagStub.tag);
+    it('should remove a tag and emit AssetUntag events for affected assets', async () => {
+      mocks.tag.getDescendantTagIds.mockResolvedValue(['tag-1']);
+      mocks.tag.getAssetIdsForTag.mockResolvedValue(['asset-1', 'asset-2']);
       mocks.tag.delete.mockResolvedValue();
 
       await sut.remove(authStub.admin, 'tag-1');
+
+      expect(mocks.tag.getDescendantTagIds).toHaveBeenCalledWith('tag-1');
+      expect(mocks.tag.getAssetIdsForTag).toHaveBeenCalledWith('tag-1');
       expect(mocks.tag.delete).toHaveBeenCalledWith('tag-1');
+      expect(mocks.event.emit).toHaveBeenNthCalledWith(1, 'AssetUntag', { assetId: 'asset-1' });
+      expect(mocks.event.emit).toHaveBeenNthCalledWith(2, 'AssetUntag', { assetId: 'asset-2' });
+    });
+
+    it('should remove a tag with descendants and emit AssetUntag events for all affected assets', async () => {
+      mocks.tag.getDescendantTagIds.mockResolvedValue(['tag-1', 'tag-1-child', 'tag-1-grandchild']);
+      mocks.tag.getAssetIdsForTag.mockResolvedValueOnce(['asset-1', 'asset-2']);
+      mocks.tag.getAssetIdsForTag.mockResolvedValueOnce(['asset-2', 'asset-3']);
+      mocks.tag.getAssetIdsForTag.mockResolvedValueOnce(['asset-4']);
+      mocks.tag.delete.mockResolvedValue();
+
+      await sut.remove(authStub.admin, 'tag-1');
+
+      expect(mocks.tag.getDescendantTagIds).toHaveBeenCalledWith('tag-1');
+      expect(mocks.tag.getAssetIdsForTag).toHaveBeenNthCalledWith(1, 'tag-1');
+      expect(mocks.tag.getAssetIdsForTag).toHaveBeenNthCalledWith(2, 'tag-1-child');
+      expect(mocks.tag.getAssetIdsForTag).toHaveBeenNthCalledWith(3, 'tag-1-grandchild');
+      expect(mocks.tag.delete).toHaveBeenCalledWith('tag-1');
+      // Should emit events for all affected assets (de-duplicated)
+      expect(mocks.event.emit).toHaveBeenCalledTimes(4);
+      expect(mocks.event.emit).toHaveBeenCalledWith('AssetUntag', { assetId: 'asset-1' });
+      expect(mocks.event.emit).toHaveBeenCalledWith('AssetUntag', { assetId: 'asset-2' });
+      expect(mocks.event.emit).toHaveBeenCalledWith('AssetUntag', { assetId: 'asset-3' });
+      expect(mocks.event.emit).toHaveBeenCalledWith('AssetUntag', { assetId: 'asset-4' });
+    });
+
+    it('should remove a tag with no affected assets', async () => {
+      mocks.tag.getDescendantTagIds.mockResolvedValue(['tag-1']);
+      mocks.tag.getAssetIdsForTag.mockResolvedValue([]);
+      mocks.tag.delete.mockResolvedValue();
+
+      await sut.remove(authStub.admin, 'tag-1');
+
+      expect(mocks.tag.getDescendantTagIds).toHaveBeenCalledWith('tag-1');
+      expect(mocks.tag.getAssetIdsForTag).toHaveBeenCalledWith('tag-1');
+      expect(mocks.tag.delete).toHaveBeenCalledWith('tag-1');
+      expect(mocks.event.emit).not.toHaveBeenCalled();
     });
   });
 
diff --git a/server/src/services/tag.service.ts b/server/src/services/tag.service.ts
index 3ee5d29b75..8c37da7a00 100644
--- a/server/src/services/tag.service.ts
+++ b/server/src/services/tag.service.ts
@@ -70,9 +70,19 @@ export class TagService extends BaseService {
   async remove(auth: AuthDto, id: string): Promise<void> {
     await this.requireAccess({ auth, permission: Permission.TagDelete, ids: [id] });
 
-    // TODO sync tag changes for affected assets
+    const descendantTagIds = await this.tagRepository.getDescendantTagIds(id);
+
+    const affectedAssetIds = new Set<string>();
+    for (const tagId of descendantTagIds) {
+      const assetIds = await this.tagRepository.getAssetIdsForTag(tagId);
+      assetIds.forEach((assetId) => affectedAssetIds.add(assetId));
+    }
 
     await this.tagRepository.delete(id);
+
+    for (const assetId of affectedAssetIds) {
+      await this.eventRepository.emit('AssetUntag', { assetId });
+    }
   }
 
   async bulkTagAssets(auth: AuthDto, dto: TagBulkAssetsDto): Promise<TagBulkAssetsResponseDto> {