diff --git a/pyproject.toml b/pyproject.toml
index bca4770..b28ce9f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "planecli"
-version = "0.3.0"
+version = "0.4.0"
 description = "CLI for Plane.so project management"
 readme = "README.md"
 license = "MIT"
diff --git a/src/planecli/commands/work_items.py b/src/planecli/commands/work_items.py
index 0b361b7..b23554a 100644
--- a/src/planecli/commands/work_items.py
+++ b/src/planecli/commands/work_items.py
@@ -220,6 +220,7 @@ async def list_(
     assignee: str | None = None,
     state: str | None = None,
     labels: str | None = None,
+    parent: str | None = None,
     sort: str = "created",
     limit: Annotated[int, Parameter(alias="-l")] = 50,
     json: bool = False,
@@ -236,6 +237,9 @@ async def list_(
         Filter by state name (comma-separated).
     labels
         Filter by label name (comma-separated).
+    parent
+        Filter by parent work item identifier (ABC-123), UUID, or name
+        (name requires --project).
     sort
         Sort by: created (default), updated.
     limit
@@ -355,6 +359,25 @@ async def _fetch_and_enrich(proj_dict: dict) -> list[dict]:
                 )
             ]
 
+    # Filter by parent work item
+    if parent:
+        if project:
+            project_id = projects_to_list[0]["id"] if projects_to_list else None
+            if project_id:
+                parent_data = await resolve_work_item_async(
+                    parent, client, workspace, project_id
+                )
+            else:
+                parent_data, _ = await resolve_work_item_across_projects_async(
+                    parent, client, workspace
+                )
+        else:
+            parent_data, _ = await resolve_work_item_across_projects_async(
+                parent, client, workspace
+            )
+        parent_id = parent_data["id"]
+        data = [d for d in data if d.get("parent") == parent_id]
+
     # Filter by labels (comma-separated, OR logic, substring match)
     if labels:
         label_tokens = [ln.strip().lower() for ln in labels.split(",") if ln.strip()]
diff --git a/tests/test_commands/test_work_items.py b/tests/test_commands/test_work_items.py
index 14342bb..ba7822f 100644
--- a/tests/test_commands/test_work_items.py
+++ b/tests/test_commands/test_work_items.py
@@ -28,6 +28,7 @@ def _make_work_item_dict(
     labels: list | None = None,
     created_at: str = "2026-02-10T12:00:00Z",
     updated_at: str = "2026-02-10T12:00:00Z",
+    parent: str | None = None,
 ) -> dict:
     """Return a work item as a dict (how cached_list_work_items returns them)."""
     return {
@@ -38,6 +39,7 @@ def _make_work_item_dict(
         "assignees": assignees or [],
         "labels": labels or [],
         "priority": "medium",
+        "parent": parent,
         "created_at": created_at,
         "updated_at": updated_at,
     }
@@ -643,6 +645,53 @@ async def test_list_filter_by_multiple_states(
         names = {d["name"] for d in data}
         assert names == {"Todo task", "Progress task"}
 
+    @patch("planecli.commands.work_items.output")
+    @patch("planecli.commands.work_items.resolve_work_item_across_projects_async")
+    @patch("planecli.commands.work_items.get_workspace", return_value="test-ws")
+    @patch("planecli.commands.work_items.get_client")
+    @patch("planecli.commands.work_items.create_client")
+    @patch("planecli.cache.cached_list_work_items", new_callable=AsyncMock)
+    @patch("planecli.cache.cached_list_members", new_callable=AsyncMock)
+    @patch("planecli.cache.cached_list_projects", new_callable=AsyncMock)
+    @patch("planecli.cache.cached_list_states", new_callable=AsyncMock)
+    @patch("planecli.cache.cached_list_labels", new_callable=AsyncMock)
+    async def test_list_filter_by_parent(
+        self,
+        mock_cached_labels,
+        mock_cached_states,
+        mock_cached_projects,
+        mock_cached_members,
+        mock_cached_work_items,
+        mock_create_client,
+        mock_get_client,
+        mock_get_ws,
+        mock_resolve_parent,
+        mock_output,
+    ):
+        """--parent ABC-1 returns only items whose parent matches the resolved UUID."""
+        mock_get_client.return_value = MagicMock()
+        mock_create_client.return_value = MagicMock()
+        mock_cached_members.return_value = []
+        mock_cached_projects.return_value = [
+            _make_project_dict("proj-1", "FE", "Frontend"),
+        ]
+        mock_cached_work_items.return_value = [
+            _make_work_item_dict("wi-1", "Child A", 1, parent="parent-uuid"),
+            _make_work_item_dict("wi-2", "Child B", 2, parent="parent-uuid"),
+            _make_work_item_dict("wi-3", "Unrelated", 3, parent="other-uuid"),
+            _make_work_item_dict("wi-4", "Orphan", 4, parent=None),
+        ]
+        mock_cached_states.return_value = []
+        mock_cached_labels.return_value = []
+        mock_resolve_parent.return_value = ({"id": "parent-uuid"}, "proj-1")
+
+        await list_(parent="FE-99")
+
+        mock_resolve_parent.assert_called_once()
+        data = mock_output.call_args[0][0]
+        names = {d["name"] for d in data}
+        assert names == {"Child A", "Child B"}
+
     @patch("planecli.commands.work_items.output")
     @patch("planecli.commands.work_items.get_workspace", return_value="test-ws")
     @patch("planecli.commands.work_items.get_client")
diff --git a/uv.lock b/uv.lock
index c501dd2..b79b274 100644
--- a/uv.lock
+++ b/uv.lock
@@ -243,7 +243,7 @@ wheels = [
 
 [[package]]
 name = "planecli"
-version = "0.2.0"
+version = "0.3.0"
 source = { editable = "." }
 dependencies = [
     { name = "cashews", extra = ["diskcache"] },