diff --git a/git-fat b/git-fat
index 5221532..cb1740e 100755
--- a/git-fat
+++ b/git-fat
@@ -11,6 +11,7 @@ import subprocess
 import shlex
 import shutil
 import itertools
+import json
 import threading
 import time
 import collections
@@ -176,6 +177,30 @@ class GitFat(object):
             raise RuntimeError('No rsync.remote in %s' % cfgpath)
         return remote, ssh_port, ssh_user, options
 
+    def list_objects(self, s3_bucket):
+        bucket = s3_bucket[5:]
+        cmd = [
+            "aws",
+            "s3api",
+            "list-objects",
+            "--bucket",
+            bucket
+        ]
+
+        process = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        out, err = process.communicate()
+
+        if out:
+            # try to parse list from json
+            data = json.loads(out)
+            keys = [key.get('Key') for key in data.get('Contents')]
+            return keys
+        else:
+            print("Failed to list bucket with error: %s" % err)
+            sys.exit(1)
+
+        return []
+
     def get_aws_cmd(self, push, s3_bucket, files):
         if not which('aws'):
             sys.stderr.write('Could not find aws cli install.\n')
@@ -183,18 +208,23 @@ class GitFat(object):
 
         if not s3_bucket.startswith('s3://'):
             s3_bucket = "s3://{}".format(s3_bucket)
+
         cmds = []
         if push:
             self.verbose('Pushing to %s' % (s3_bucket))
+            remote_files = self.list_objects(s3_bucket)
             for file in files:
-                cmd = [
-                    "aws",
-                    "s3",
-                    "cp",
-                    self.objdir + "/" + file,
-                    s3_bucket + "/" + file
-                ]
-                cmds.append(cmd)
+                # only push files that do not exist in the remote
+                if file not in remote_files:
+                    self.verbose("%s does not exist in remote, will be pushed" % file)
+                    cmd = [
+                        "aws",
+                        "s3",
+                        "cp",
+                        self.objdir + "/" + file,
+                        s3_bucket + "/" + file
+                    ]
+                    cmds.append(cmd)
         else:
             self.verbose('Pulling from %s' % (s3_bucket))
             for file in files:
@@ -206,6 +236,7 @@ class GitFat(object):
                     self.objdir + "/" + file
                 ]
                 cmds.append(cmd)
+
         return cmds
 
     def get_rsync_command(self,push,files):