diff --git a/ec2/spark_ec2.py b/ec2/spark_ec2.py
index 92adfd2d07b5bbac0e8335faba6f11d1498a6937..4e8f5c1f44041634182517b31640f6dfd781f82b 100755
--- a/ec2/spark_ec2.py
+++ b/ec2/spark_ec2.py
@@ -120,6 +120,10 @@ def parse_args():
              "Only possible on EBS-backed AMIs. " +
              "EBS volumes are only attached if --ebs-vol-size > 0." +
              "Only support up to 8 EBS volumes.")
+    parser.add_option("--placement-group", type="string", default=None,
+                      help="Which placement group to try and launch " +
+                      "instances into. Assumes placement group is already " +
+                      "created.")
     parser.add_option(
         "--swap", metavar="SWAP", type="int", default=1024,
         help="Swap space to set up per node, in MB (default: %default)")
@@ -429,6 +433,7 @@ def launch_cluster(conn, opts, cluster_name):
                 instance_type=opts.instance_type,
                 block_device_map=block_map,
                 subnet_id=opts.subnet_id,
+                placement_group=opts.placement_group,
                 user_data=user_data_content)
             my_req_ids += [req.id for req in slave_reqs]
             i += 1
@@ -482,6 +487,7 @@ def launch_cluster(conn, opts, cluster_name):
                                       max_count=num_slaves_this_zone,
                                       block_device_map=block_map,
                                       subnet_id=opts.subnet_id,
+                                      placement_group=opts.placement_group,
                                       user_data=user_data_content)
                 slave_nodes += slave_res.instances
                 print "Launched %d slaves in %s, regid = %s" % (num_slaves_this_zone,
@@ -509,7 +515,9 @@ def launch_cluster(conn, opts, cluster_name):
                                max_count=1,
                                block_device_map=block_map,
                                subnet_id=opts.subnet_id,
+                               placement_group=opts.placement_group,
                                user_data=user_data_content)
+
         master_nodes = master_res.instances
         print "Launched master in %s, regid = %s" % (zone, master_res.id)