diff -r 84d752c3ab6f Doc/library/concurrent.futures.rst
--- a/Doc/library/concurrent.futures.rst	Sat Feb 25 00:47:08 2012 +0100
+++ b/Doc/library/concurrent.futures.rst	Mon Feb 27 15:00:14 2012 -0800
@@ -114,10 +114,12 @@
    executor.submit(wait_on_future)
 
 
-.. class:: ThreadPoolExecutor(max_workers)
+.. class:: ThreadPoolExecutor(max_workers, queue_size=0)
 
    An :class:`Executor` subclass that uses a pool of at most *max_workers*
-   threads to execute calls asynchronously.
+   threads to execute calls asynchronously. Parameter *queue_size* is used to
+   initialize an internal work queue object. If a non-positive number is given,
+   this queue is unbounded.
 
 
 .. _threadpoolexecutor-example:
diff -r 84d752c3ab6f Lib/concurrent/futures/thread.py
--- a/Lib/concurrent/futures/thread.py	Sat Feb 25 00:47:08 2012 +0100
+++ b/Lib/concurrent/futures/thread.py	Mon Feb 27 15:00:14 2012 -0800
@@ -78,15 +78,19 @@
         _base.LOGGER.critical('Exception in worker', exc_info=True)
 
 class ThreadPoolExecutor(_base.Executor):
-    def __init__(self, max_workers):
+    def __init__(self, max_workers, queue_size=0):
         """Initializes a new ThreadPoolExecutor instance.
 
         Args:
             max_workers: The maximum number of threads that can be used to
                 execute the given calls.
+            queue_size: The maximum number of jobs that can be submitted to
+                this executor. Any job after this threshold will block the
+                executor until the queue is freed up. If non-positive number
+                is supplied, the queue is infinite. Default to 0.
         """
         self._max_workers = max_workers
-        self._work_queue = queue.Queue()
+        self._work_queue = queue.Queue(queue_size)
         self._threads = set()
         self._shutdown = False
         self._shutdown_lock = threading.Lock()