diff -r a6892bd4f752 Lib/asyncio/queues.py
--- a/Lib/asyncio/queues.py	Wed Jun 11 06:19:47 2014 -0700
+++ b/Lib/asyncio/queues.py	Wed Jun 11 22:53:53 2014 +0700
@@ -105,7 +105,7 @@
         if self._maxsize <= 0:
             return False
         else:
-            return self.qsize() == self._maxsize
+            return self.qsize() >= self._maxsize
 
     @coroutine
     def put(self, item):
@@ -126,7 +126,7 @@
             self._put(item)
             getter.set_result(self._get())
 
-        elif self._maxsize > 0 and self._maxsize == self.qsize():
+        elif self._maxsize > 0 and self._maxsize <= self.qsize():
             waiter = futures.Future(loop=self._loop)
 
             self._putters.append((item, waiter))
@@ -152,7 +152,7 @@
             self._put(item)
             getter.set_result(self._get())
 
-        elif self._maxsize > 0 and self._maxsize == self.qsize():
+        elif self._maxsize > 0 and self._maxsize <= self.qsize():
             raise QueueFull
         else:
             self._put(item)
diff -r a6892bd4f752 Lib/test/test_asyncio/test_queues.py
--- a/Lib/test/test_asyncio/test_queues.py	Wed Jun 11 06:19:47 2014 -0700
+++ b/Lib/test/test_asyncio/test_queues.py	Wed Jun 11 22:53:53 2014 +0700
@@ -339,6 +339,21 @@
         q.put_nowait(1)
         self.assertRaises(asyncio.QueueFull, q.put_nowait, 2)
 
+    def test_float_maxsize(self):
+        q = asyncio.Queue(maxsize=1.3, loop=self.loop)
+        q.put_nowait(1)
+        q.put_nowait(2)
+        self.assertTrue(q.full())
+        self.assertRaises(asyncio.QueueFull, q.put_nowait, 3)
+
+        q = asyncio.Queue(maxsize=1.3, loop=self.loop)
+        @asyncio.coroutine
+        def queue_put():
+            yield from q.put(1)
+            yield from q.put(2)
+            self.assertTrue(q.full())
+        self.loop.run_until_complete(queue_put())
+
     def test_put_cancelled(self):
         q = asyncio.Queue(loop=self.loop)