diff --git a/frontend/src/lib/components/TagParentPicker.svelte b/frontend/src/lib/components/TagParentPicker.svelte
index 9e12bd10..a67faef9 100644
--- a/frontend/src/lib/components/TagParentPicker.svelte
+++ b/frontend/src/lib/components/TagParentPicker.svelte
@@ -25,6 +25,8 @@ $effect(() => {
 	displayName = initialName;
 });
 
+// Uses fetch directly (not the typed api client) because this component runs in the browser
+// where the typed api client is not available, and the tags endpoint needs no auth cookie.
 const typeahead = createTypeahead<Tag>({
 	fetchUrl: async (q) => {
 		const res = await fetch(`/api/tags?query=${encodeURIComponent(q)}`);
@@ -38,6 +40,8 @@ const filteredResults = $derived(typeahead.results.filter((t) => !excludeIds.inc
 function handleInput() {
 	const term = untrack(() => displayName);
 	typeahead.setQuery(term);
+	// Reset active index whenever results are re-fetched
+	typeahead.setActiveIndex(-1);
 }
 
 function selectTag(tag: Tag) {
@@ -51,6 +55,25 @@ function clearSelection() {
 	displayName = '';
 	typeahead.close();
 }
+
+function handleKeydown(e: KeyboardEvent) {
+	if (!typeahead.isOpen) return;
+	const len = filteredResults.length;
+	if (len === 0) return;
+
+	if (e.key === 'ArrowDown') {
+		e.preventDefault();
+		typeahead.setActiveIndex((typeahead.activeIndex + 1) % len);
+	} else if (e.key === 'ArrowUp') {
+		e.preventDefault();
+		typeahead.setActiveIndex((typeahead.activeIndex - 1 + len) % len);
+	} else if (e.key === 'Enter' && typeahead.activeIndex >= 0) {
+		e.preventDefault();
+		selectTag(filteredResults[typeahead.activeIndex]);
+	} else if (e.key === 'Escape') {
+		typeahead.close();
+	}
+}
 </script>
 
 <div class="relative" use:clickOutside onclickoutside={() => typeahead.close()}>
@@ -65,8 +88,12 @@ function clearSelection() {
 			aria-expanded={typeahead.isOpen}
 			aria-controls="{name}-listbox"
 			aria-autocomplete="list"
+			aria-activedescendant={typeahead.activeIndex >= 0
+				? `${name}-option-${typeahead.activeIndex}`
+				: undefined}
 			bind:value={displayName}
 			oninput={handleInput}
+			onkeydown={handleKeydown}
 			placeholder={m.admin_tag_parent_placeholder()}
 			class="mt-1 block w-full rounded-md border border-line bg-surface p-2 pr-8 text-ink shadow-sm placeholder:text-ink-3 focus:outline-none focus-visible:ring-2 focus-visible:ring-focus-ring"
 		/>
@@ -96,13 +123,15 @@ function clearSelection() {
 			role="listbox"
 			class="ring-opacity-5 absolute top-full left-0 z-50 mt-1 max-h-60 w-full overflow-auto rounded-md bg-surface py-1 text-base shadow-lg ring-1 ring-black focus:outline-none sm:text-sm"
 		>
-			{#each filteredResults as tag (tag.id)}
+			{#each filteredResults as tag, i (tag.id)}
 				<div
-					class="relative cursor-pointer py-2 pr-9 pl-3 text-ink select-none hover:bg-accent-bg"
+					id="{name}-option-{i}"
+					role="option"
+					tabindex="-1"
+					aria-selected={i === typeahead.activeIndex}
+					class="relative cursor-pointer py-2 pr-9 pl-3 text-ink select-none hover:bg-accent-bg {i === typeahead.activeIndex ? 'bg-accent-bg' : ''}"
 					onclick={() => selectTag(tag)}
 					onkeydown={(e) => e.key === 'Enter' && selectTag(tag)}
-					role="button"
-					tabindex="0"
 				>
 					<span class="block truncate font-medium">{tag.name}</span>
 					{#if tag.parentId}
diff --git a/frontend/src/lib/components/TagParentPicker.svelte.spec.ts b/frontend/src/lib/components/TagParentPicker.svelte.spec.ts
index f2c2bb0c..e5311983 100644
--- a/frontend/src/lib/components/TagParentPicker.svelte.spec.ts
+++ b/frontend/src/lib/components/TagParentPicker.svelte.spec.ts
@@ -83,7 +83,7 @@ describe('TagParentPicker – selection', () => {
 		await input.fill('H');
 		await vi.advanceTimersByTimeAsync(300);
 
-		document.querySelector<HTMLElement>('[role="button"]')!.click();
+		await page.getByRole('option', { name: 'Haus' }).click();
 		await vi.advanceTimersByTimeAsync(0);
 
 		expect(hiddenInput('parentId')?.value).toBe('t1');
@@ -97,7 +97,7 @@ describe('TagParentPicker – selection', () => {
 		await input.fill('H');
 		await vi.advanceTimersByTimeAsync(300);
 
-		document.querySelector<HTMLElement>('[role="button"]')!.click();
+		await page.getByRole('option', { name: 'Haus' }).click();
 		await vi.advanceTimersByTimeAsync(0);
 
 		await expect
@@ -113,15 +113,52 @@ describe('TagParentPicker – selection', () => {
 		await input.fill('H');
 		await vi.advanceTimersByTimeAsync(300);
 
-		document.querySelector<HTMLElement>('[role="button"]')!.click();
+		await page.getByRole('option', { name: 'Haus' }).click();
 		await vi.advanceTimersByTimeAsync(0);
 
 		expect(hiddenInput('parentId')?.value).toBe('t1');
 
-		const clearBtn = document.querySelector<HTMLElement>('button[aria-label="Auswahl entfernen"]')!;
-		clearBtn.click();
+		await page.getByRole('button', { name: 'Auswahl entfernen' }).click();
 		await vi.advanceTimersByTimeAsync(0);
 
 		expect(hiddenInput('parentId')?.value).toBe('');
 	});
 });
+
+// ─── ARIA combobox ────────────────────────────────────────────────────────────
+
+describe('TagParentPicker – ARIA combobox', () => {
+	it('ArrowDown moves aria-activedescendant to first option', async () => {
+		mockFetchWithTags([
+			{ id: 't1', name: 'Haus' },
+			{ id: 't2', name: 'Garten' }
+		]);
+		render(TagParentPicker, { name: 'parentId' });
+
+		const input = page.getByRole('combobox');
+		await input.fill('a');
+		await vi.advanceTimersByTimeAsync(300);
+
+		// Dropdown is open — arrow down should highlight first option
+		const el = await input.element();
+		el.dispatchEvent(
+			new KeyboardEvent('keydown', { key: 'ArrowDown', bubbles: true, cancelable: true })
+		);
+		await vi.advanceTimersByTimeAsync(0);
+
+		expect(el.getAttribute('aria-activedescendant')).toBe('parentId-option-0');
+	});
+
+	it('listbox items have role="option" with ids', async () => {
+		mockFetchWithTags([{ id: 't1', name: 'Haus' }]);
+		render(TagParentPicker, { name: 'parentId' });
+
+		const input = page.getByRole('combobox');
+		await input.fill('H');
+		await vi.advanceTimersByTimeAsync(300);
+
+		await expect.element(page.getByRole('option', { name: 'Haus' })).toBeInTheDocument();
+		const option = await page.getByRole('option', { name: 'Haus' }).element();
+		expect(option.id).toBe('parentId-option-0');
+	});
+});