diff --git a/python/packages/autogen-agentchat/tests/test_assistant_agent.py b/python/packages/autogen-agentchat/tests/test_assistant_agent.py
index e477ed3f1245..7b281e39f6f5 100644
--- a/python/packages/autogen-agentchat/tests/test_assistant_agent.py
+++ b/python/packages/autogen-agentchat/tests/test_assistant_agent.py
@@ -17,10 +17,10 @@
     ToolCallRequestEvent,
     ToolCallSummaryMessage,
 )
-from autogen_core import Image
+from autogen_core import FunctionCall, Image
 from autogen_core.memory import ListMemory, Memory, MemoryContent, MemoryMimeType, MemoryQueryResult
 from autogen_core.model_context import BufferedChatCompletionContext
-from autogen_core.models import LLMMessage
+from autogen_core.models import FunctionExecutionResult, LLMMessage
 from autogen_core.models._model_client import ModelFamily
 from autogen_core.tools import FunctionTool
 from autogen_ext.models.openai import OpenAIChatCompletionClient
@@ -281,6 +281,142 @@ async def test_run_with_tools_and_reflection(monkeypatch: pytest.MonkeyPatch) ->
     assert state == state2
 
 
+@pytest.mark.asyncio
+async def test_run_with_parallel_tools(monkeypatch: pytest.MonkeyPatch) -> None:
+    model = "gpt-4o-2024-05-13"
+    chat_completions = [
+        ChatCompletion(
+            id="id1",
+            choices=[
+                Choice(
+                    finish_reason="tool_calls",
+                    index=0,
+                    message=ChatCompletionMessage(
+                        content=None,
+                        tool_calls=[
+                            ChatCompletionMessageToolCall(
+                                id="1",
+                                type="function",
+                                function=Function(
+                                    name="_pass_function",
+                                    arguments=json.dumps({"input": "task1"}),
+                                ),
+                            ),
+                            ChatCompletionMessageToolCall(
+                                id="2",
+                                type="function",
+                                function=Function(
+                                    name="_pass_function",
+                                    arguments=json.dumps({"input": "task2"}),
+                                ),
+                            ),
+                            ChatCompletionMessageToolCall(
+                                id="3",
+                                type="function",
+                                function=Function(
+                                    name="_echo_function",
+                                    arguments=json.dumps({"input": "task3"}),
+                                ),
+                            ),
+                        ],
+                        role="assistant",
+                    ),
+                )
+            ],
+            created=0,
+            model=model,
+            object="chat.completion",
+            usage=CompletionUsage(prompt_tokens=10, completion_tokens=5, total_tokens=0),
+        ),
+        ChatCompletion(
+            id="id2",
+            choices=[
+                Choice(
+                    finish_reason="stop",
+                    index=0,
+                    message=ChatCompletionMessage(content="pass", role="assistant"),
+                )
+            ],
+            created=0,
+            model=model,
+            object="chat.completion",
+            usage=CompletionUsage(prompt_tokens=10, completion_tokens=5, total_tokens=0),
+        ),
+        ChatCompletion(
+            id="id2",
+            choices=[
+                Choice(
+                    finish_reason="stop",
+                    index=0,
+                    message=ChatCompletionMessage(content="TERMINATE", role="assistant"),
+                )
+            ],
+            created=0,
+            model=model,
+            object="chat.completion",
+            usage=CompletionUsage(prompt_tokens=10, completion_tokens=5, total_tokens=0),
+        ),
+    ]
+    mock = _MockChatCompletion(chat_completions)
+    monkeypatch.setattr(AsyncCompletions, "create", mock.mock_create)
+    agent = AssistantAgent(
+        "tool_use_agent",
+        model_client=OpenAIChatCompletionClient(model=model, api_key=""),
+        tools=[
+            _pass_function,
+            _fail_function,
+            FunctionTool(_echo_function, description="Echo"),
+        ],
+    )
+    result = await agent.run(task="task")
+
+    assert len(result.messages) == 4
+    assert isinstance(result.messages[0], TextMessage)
+    assert result.messages[0].models_usage is None
+    assert isinstance(result.messages[1], ToolCallRequestEvent)
+    assert result.messages[1].content == [
+        FunctionCall(id="1", arguments=r'{"input": "task1"}', name="_pass_function"),
+        FunctionCall(id="2", arguments=r'{"input": "task2"}', name="_pass_function"),
+        FunctionCall(id="3", arguments=r'{"input": "task3"}', name="_echo_function"),
+    ]
+    assert result.messages[1].models_usage is not None
+    assert result.messages[1].models_usage.completion_tokens == 5
+    assert result.messages[1].models_usage.prompt_tokens == 10
+    assert isinstance(result.messages[2], ToolCallExecutionEvent)
+    expected_content = [
+        FunctionExecutionResult(call_id="1", content="pass"),
+        FunctionExecutionResult(call_id="2", content="pass"),
+        FunctionExecutionResult(call_id="3", content="task3"),
+    ]
+    for expected in expected_content:
+        assert expected in result.messages[2].content
+    assert result.messages[2].models_usage is None
+    assert isinstance(result.messages[3], ToolCallSummaryMessage)
+    assert result.messages[3].content == "pass\npass\ntask3"
+    assert result.messages[3].models_usage is None
+
+    # Test streaming.
+    mock.curr_index = 0  # Reset the mock
+    index = 0
+    async for message in agent.run_stream(task="task"):
+        if isinstance(message, TaskResult):
+            assert message == result
+        else:
+            assert message == result.messages[index]
+            index += 1
+
+    # Test state saving and loading.
+    state = await agent.save_state()
+    agent2 = AssistantAgent(
+        "tool_use_agent",
+        model_client=OpenAIChatCompletionClient(model=model, api_key=""),
+        tools=[_pass_function, _fail_function, FunctionTool(_echo_function, description="Echo")],
+    )
+    await agent2.load_state(state)
+    state2 = await agent2.save_state()
+    assert state == state2
+
+
 @pytest.mark.asyncio
 async def test_handoffs(monkeypatch: pytest.MonkeyPatch) -> None:
     handoff = Handoff(target="agent2")