diff --git a/starlette/testclient.py b/starlette/testclient.py
index 1d5e90dc8..c146eed3d 100644
--- a/starlette/testclient.py
+++ b/starlette/testclient.py
@@ -10,6 +10,7 @@
 from urllib.parse import unquote, urljoin, urlsplit
 
 import requests
+from urllib3.util.timeout import Timeout
 
 from starlette.types import Message, Receive, Scope, Send
 from starlette.websockets import WebSocketDisconnect
@@ -96,7 +97,11 @@ def __init__(
         self.root_path = root_path
 
     def send(
-        self, request: requests.PreparedRequest, *args: typing.Any, **kwargs: typing.Any
+        self,
+        request: requests.PreparedRequest,
+        *args: typing.Any,
+        timeout: Timeout = None,
+        **kwargs: typing.Any,
     ) -> requests.Response:
         scheme, netloc, path, query, fragment = (
             str(item) for item in urlsplit(request.url)
@@ -237,7 +242,15 @@ async def send(message: Message) -> None:
             asyncio.set_event_loop(loop)
 
         try:
-            loop.run_until_complete(self.app(scope, receive, send))
+            if isinstance(timeout, tuple):
+                err = (
+                    "Invalid timeout {}. testclient only supports float (not tuple)"
+                    "at this time ".format(timeout)
+                )
+                raise ValueError(err)
+            loop.run_until_complete(
+                asyncio.wait_for(self.app(scope, receive, send), timeout)
+            )
         except BaseException as exc:
             if self.raise_server_exceptions:
                 raise exc from None
diff --git a/tests/test_testclient.py b/tests/test_testclient.py
index 00f4e0125..d702ad195 100644
--- a/tests/test_testclient.py
+++ b/tests/test_testclient.py
@@ -1,4 +1,5 @@
 import asyncio
+import time
 
 import pytest
 
@@ -16,6 +17,19 @@ def mock_service_endpoint(request):
     return JSONResponse({"mock": "example"})
 
 
+@mock_service.route("/slow_response")
+def slow_response(request):
+    time.sleep(0.01)
+    return JSONResponse({"mock": "slow example"})
+
+
+@mock_service.route("/async_slow_response")
+async def async_slow_response(request):
+    # time.sleep(0.01)
+    await asyncio.sleep(0.01)
+    return JSONResponse({"mock": "slow example"})
+
+
 app = Starlette()
 
 
@@ -132,3 +146,34 @@ async def asgi(receive, send):
     with client.websocket_connect("/") as websocket:
         data = websocket.receive_json()
         assert data == {"message": "test"}
+
+
+@pytest.mark.parametrize("endpoint", ["/slow_response", "/async_slow_response"])
+def test_timeout(endpoint):
+    client = TestClient(mock_service, raise_server_exceptions=True)
+
+    with pytest.raises(ValueError):
+        client.get(endpoint, timeout=(1, 1))
+
+    with pytest.raises(asyncio.TimeoutError):
+        client.get(endpoint, timeout=0.001)
+
+    response = client.get(endpoint, timeout=1)
+    assert response.json() == {"mock": "slow example"}
+
+    response = client.get(endpoint)
+    assert response.json() == {"mock": "slow example"}
+
+    client = TestClient(mock_service, raise_server_exceptions=False)
+
+    response = client.get(endpoint, timeout=(1, 1))
+    assert response.status_code == 500
+
+    response = client.get(endpoint, timeout=0.001)
+    assert response.status_code == 500
+
+    response = client.get(endpoint, timeout=1)
+    assert response.json() == {"mock": "slow example"}
+
+    response = client.get(endpoint)
+    assert response.json() == {"mock": "slow example"}