diff --git a/tests/unit/vertex_adk/test_agent_engine_templates_adk.py b/tests/unit/vertex_adk/test_agent_engine_templates_adk.py
index 93b10c1214..c3dc17c6a5 100644
--- a/tests/unit/vertex_adk/test_agent_engine_templates_adk.py
+++ b/tests/unit/vertex_adk/test_agent_engine_templates_adk.py
@@ -506,6 +506,43 @@ async def test_streaming_agent_run_with_events(
             events.append(event)
         assert len(events) == 1
 
+    @pytest.mark.asyncio
+    async def test_streaming_agent_run_with_events_extracts_user_id_from_headers(
+        self,
+        default_instrumentor_builder_mock: mock.Mock,
+        get_project_id_mock: mock.Mock,
+    ):
+        app = agent_engines.AdkApp(agent=_TEST_AGENT)
+        app.set_up()
+        app._tmpl_attrs["in_memory_runner"] = _MockRunner()
+
+        request_json = json.dumps(
+            {
+                "message": {
+                    "parts": [{"text": "Hello"}],
+                    "role": "user",
+                },
+            }
+        )
+        headers = {
+            "X-Goog-Authenticated-User-Email": "test_user_from_header@google.com"
+        }
+
+        with mock.patch.object(app, "_init_session") as mock_init_session:
+            mock_session = mock.Mock()
+            mock_session.id = "mock_session_id"
+            mock_init_session.return_value = mock_session
+
+            async for _ in app.streaming_agent_run_with_events(
+                request_json=request_json, headers=headers
+            ):
+                pass
+
+            mock_init_session.assert_called_once()
+            # Assert that the extracted request object correctly pulled the user_id from headers
+            request_obj = mock_init_session.call_args.kwargs["request"]
+            assert request_obj.user_id == "test_user_from_header@google.com"
+
     @pytest.mark.asyncio
     @mock.patch.dict(
         os.environ,
diff --git a/vertexai/agent_engines/templates/adk.py b/vertexai/agent_engines/templates/adk.py
index 6bab24f0a2..57cf8aaf88 100644
--- a/vertexai/agent_engines/templates/adk.py
+++ b/vertexai/agent_engines/templates/adk.py
@@ -195,9 +195,14 @@ def __init__(self, **kwargs):
         )
         # The authorizations of the user, keyed by authorization ID.
 
-        self.user_id: Optional[str] = kwargs.get("user_id") or kwargs.get(
-            "userId", _DEFAULT_USER_ID
-        )
+        extracted_user_id = kwargs.get("user_id") or kwargs.get("userId")
+        if not extracted_user_id:
+            headers = kwargs.get("headers", {})
+            extracted_user_id = headers.get(
+                "X-Goog-Authenticated-User-Email"
+            ) or headers.get("X-Endpoint-API-UserInfo")
+
+        self.user_id: Optional[str] = extracted_user_id or _DEFAULT_USER_ID
         # The user ID.
 
         self.session_id: Optional[str] = kwargs.get("session_id") or kwargs.get(
@@ -1195,7 +1200,9 @@ def stream_query(
             ):
                 yield _utils.dump_event_for_json(event)
 
-    async def streaming_agent_run_with_events(self, request_json: str):
+    async def streaming_agent_run_with_events(
+        self, request_json: str, headers: Optional[Dict[str, str]] = None
+    ):
         """Streams responses asynchronously from the ADK application.
 
         In general, you should use `async_stream_query` instead, as it has a
@@ -1206,13 +1213,18 @@ async def streaming_agent_run_with_events(self, request_json: str):
         Args:
             request_json (str):
                 Required. The request to stream responses for.
+            headers (Dict[str, str]):
+                Optional. The HTTP request headers containing IAM metadata.
         """
 
         import json
         from google.genai import types
         from google.genai.errors import ClientError
 
-        request = _StreamRunRequest(**json.loads(request_json))
+        payload = json.loads(request_json)
+        if headers:
+            payload["headers"] = headers
+        request = _StreamRunRequest(**payload)
         if not any(
             self._tmpl_attrs.get(service)
             for service in (