diff --git a/rxjava-core/src/main/java/rx/subjects/AsyncSubject.java b/rxjava-core/src/main/java/rx/subjects/AsyncSubject.java
new file mode 100644
index 0000000000..f496b76e4b
--- /dev/null
+++ b/rxjava-core/src/main/java/rx/subjects/AsyncSubject.java
@@ -0,0 +1,253 @@
+/**
+ * Copyright 2013 Netflix, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package rx.subjects;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Matchers.anyString;
+
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.junit.Test;
+import org.mockito.Mockito;
+
+import rx.Observer;
+import rx.Subscription;
+import rx.util.AtomicObservableSubscription;
+import rx.util.SynchronizedObserver;
+import rx.util.functions.Action1;
+import rx.util.functions.Func0;
+import rx.util.functions.Func1;
+
+/**
+ * Subject that publishes only the last event to each {@link Observer} that has subscribed when the completes.
+ *
+ * Example usage:
+ *
+ *
{@code
+
+ // observer will receive no onNext events.
+ AsyncSubject