diff --git a/src/java/com/twitter/common/zookeeper/ZooKeeperMap.java b/src/java/com/twitter/common/zookeeper/ZooKeeperMap.java
index 478f1404f..dc97080b6 100644
--- a/src/java/com/twitter/common/zookeeper/ZooKeeperMap.java
+++ b/src/java/com/twitter/common/zookeeper/ZooKeeperMap.java
@@ -65,6 +65,29 @@
  */
 public class ZooKeeperMap<V> extends ForwardingMap<String, V> {
 
+  /**
+   * An optional listener which can be supplied and triggered when entries in a ZooKeeperMap
+   * are changed or removed. For a ZooKeeperMap of type <V>, the listener will fire a "nodeChanged"
+   * event with the name of the ZNode that changed, and its resulting value as interpreted by the
+   * provided deserializer. Removal of child nodes triggers the "nodeRemoved" method indicating the
+   * name of the ZNode which is no longer present in the map.
+   */
+  public interface ZKMapListener<V> {
+    
+    /**
+     * Fired when a node is added to the ZooKeeperMap or changed.
+     * @param nodeName indicates the name of the ZNode that was added or changed.
+     * @param value is the new value of the node after passing through your supplied deserializer.
+    */
+    public void nodeChanged(String nodeName, V value);
+
+    /**
+     * Fired when a node is removed from the ZooKeeperMap.
+     * @param nodeName indicates the name of the ZNode that was removed from the ZooKeeperMap.
+    */
+    public void nodeRemoved(String nodeName);
+  }
+
   /**
    * Default deserializer for the constructor if you want to simply store the zookeeper byte[] data
    * in this map.
@@ -80,6 +103,8 @@ public class ZooKeeperMap<V> extends ForwardingMap<String, V> {
   private final ConcurrentMap<String, V> localMap;
   private final BackoffHelper backoffHelper;
 
+  private final ZKMapListener<V> mapListener;
+
   // Whether it's safe to re-establish watches if our zookeeper session has expired.
   private final Object safeToRewatchLock;
   private volatile boolean safeToRewatch;
@@ -92,6 +117,7 @@ public class ZooKeeperMap<V> extends ForwardingMap<String, V> {
    * @param nodePath path to a node whose data will be watched
    * @param deserializer a function that converts byte[] data from a zk node to this map's
    *     value type V
+   * @param listener is a ZKMapListener which fires when values are added, changed, or removed.
    *
    * @throws InterruptedException if the underlying zookeeper server transaction is interrupted
    * @throws KeeperException.NoNodeException if the given nodePath doesn't exist
@@ -100,13 +126,34 @@ public class ZooKeeperMap<V> extends ForwardingMap<String, V> {
    *     cluster
    */
   public static <V> ZooKeeperMap<V> create(ZooKeeperClient zkClient, String nodePath,
-      Function<byte[], V> deserializer) throws InterruptedException, KeeperException,
+      Function<byte[], V> deserializer, ZKMapListener<V> listener) throws InterruptedException, KeeperException,
       ZooKeeperConnectionException {
-    ZooKeeperMap<V> zkMap = new ZooKeeperMap<V>(zkClient, nodePath, deserializer);
+    ZooKeeperMap<V> zkMap = new ZooKeeperMap<V>(zkClient, nodePath, deserializer, listener);
     zkMap.init();
     return zkMap;
   }
 
+  /**
+   * Returns an initialized ZooKeeperMap.  The given path must exist at the time of
+   * creation or a {@link KeeperException} will be thrown.
+   *
+   * @param zkClient a zookeeper client
+   * @param nodePath path to a node whose data will be watched
+   * @param deserializer a function that converts byte[] data from a zk node to this map's
+   *     value type V
+   *
+   * @throws InterruptedException if the underlying zookeeper server transaction is interrupted
+   * @throws KeeperException.NoNodeException if the given nodePath doesn't exist
+   * @throws KeeperException if the server signals an error
+   * @throws ZooKeeperConnectionException if there was a problem connecting to the zookeeper
+   *     cluster
+   */
+  public static <V> ZooKeeperMap<V> create(ZooKeeperClient zkClient, String nodePath,
+      Function<byte[], V> deserializer) throws InterruptedException, KeeperException,
+      ZooKeeperConnectionException {
+    return ZooKeeperMap.create(zkClient, nodePath, deserializer, null);
+  }
+
   /**
    * Initializes a ZooKeeperMap.  The given path must exist at the time of object creation or
    * a {@link KeeperException} will be thrown.
@@ -119,6 +166,7 @@ public static <V> ZooKeeperMap<V> create(ZooKeeperClient zkClient, String nodePa
    * @param nodePath top-level node path under which the map data lives
    * @param deserializer a function that converts byte[] data from a zk node to this map's
    *     value type V
+   * @param listener is a ZKMapListener which fires when values are added, changed, or removed.
    *
    * @throws InterruptedException if the underlying zookeeper server transaction is interrupted
    * @throws KeeperException.NoNodeException if the given nodePath doesn't exist
@@ -128,9 +176,10 @@ public static <V> ZooKeeperMap<V> create(ZooKeeperClient zkClient, String nodePa
    */
   @VisibleForTesting
   ZooKeeperMap(ZooKeeperClient zkClient, String nodePath,
-      Function<byte[], V> deserializer) throws InterruptedException, KeeperException,
+      Function<byte[], V> deserializer, ZKMapListener<V> mapListener) throws InterruptedException, KeeperException,
       ZooKeeperConnectionException {
     super();
+    this.mapListener = mapListener;
     this.zkClient = Preconditions.checkNotNull(zkClient);
     this.nodePath = MorePreconditions.checkNotBlank(nodePath);
     this.deserializer = Preconditions.checkNotNull(deserializer);
@@ -145,6 +194,32 @@ public static <V> ZooKeeperMap<V> create(ZooKeeperClient zkClient, String nodePa
     }
   }
 
+  /**
+   * Initializes a ZooKeeperMap.  The given path must exist at the time of object creation or
+   * a {@link KeeperException} will be thrown.
+   *
+   * Please note that this object will not track any remote zookeeper data until {@link #init()}
+   * is successfully called.  After construction and before that call, this {@link Map} will
+   * be empty.
+   *
+   * @param zkClient a zookeeper client
+   * @param nodePath top-level node path under which the map data lives
+   * @param deserializer a function that converts byte[] data from a zk node to this map's
+   *     value type V
+   *
+   * @throws InterruptedException if the underlying zookeeper server transaction is interrupted
+   * @throws KeeperException.NoNodeException if the given nodePath doesn't exist
+   * @throws KeeperException if the server signals an error
+   * @throws ZooKeeperConnectionException if there was a problem connecting to the zookeeper
+   *     cluster
+   */
+   @VisibleForTesting
+   ZooKeeperMap(ZooKeeperClient zkClient, String nodePath,
+       Function<byte[], V> deserializer) throws InterruptedException, KeeperException,
+       ZooKeeperConnectionException {
+     this(zkClient, nodePath, deserializer, null);
+   }
+
   /**
    * Initialize zookeeper tracking for this {@link Map}.  Once this call returns, this object
    * will be tracking data in zookeeper.
@@ -331,11 +406,13 @@ public void process(WatchedEvent event) {
   @VisibleForTesting
   void removeEntry(String key) {
     localMap.remove(key);
+    if (mapListener != null) mapListener.nodeRemoved(key);
   }
 
   @VisibleForTesting
   void putEntry(String key, V value) {
     localMap.put(key, value);
+    if (mapListener != null) mapListener.nodeChanged(key, value);
   }
 
   private void rewatchDataNodes() throws InterruptedException {