diff --git a/moto/s3/models.py b/moto/s3/models.py
index 0abc3e4c2..a97e28627 100644
--- a/moto/s3/models.py
+++ b/moto/s3/models.py
@@ -164,6 +164,10 @@ class S3Backend(BaseBackend):
 
         return self.set_key(bucket_name, multipart.key_name, value)
 
+    def cancel_multipart(self, bucket_name, multipart_id):
+        bucket = self.buckets[bucket_name]
+        del bucket.multiparts[multipart_id]
+
     def list_multipart(self, bucket_name, multipart_id):
         bucket = self.buckets[bucket_name]
         return bucket.multiparts[multipart_id].list_parts()
diff --git a/moto/s3/responses.py b/moto/s3/responses.py
index ded07e2f0..b2ff1b60b 100644
--- a/moto/s3/responses.py
+++ b/moto/s3/responses.py
@@ -188,6 +188,10 @@ def _key_response(request, full_url, headers):
         else:
             return 404, headers, ""
     elif method == 'DELETE':
+        if 'uploadId' in query:
+            upload_id = query['uploadId'][0]
+            s3_backend.cancel_multipart(bucket_name, upload_id)
+            return 204, headers, ""
         removed_key = s3_backend.delete_key(bucket_name, key_name)
         template = Template(S3_DELETE_OBJECT_SUCCESS)
         return 204, headers, template.render(bucket=removed_key)