diff --git a/tempest/api/compute/admin/test_aggregates.py b/tempest/api/compute/admin/test_aggregates.py
index e8acec5..4ff6b07 100644
--- a/tempest/api/compute/admin/test_aggregates.py
+++ b/tempest/api/compute/admin/test_aggregates.py
@@ -85,7 +85,7 @@
                           aggregates))
 
     @attr(type='gate')
-    def test_aggregate_create_get_details(self):
+    def test_aggregate_create_update_metadata_get_details(self):
         # Create an aggregate and ensure its details are returned.
         aggregate_name = rand_name(self.aggregate_name_prefix)
         resp, aggregate = self.client.create_aggregate(aggregate_name)
@@ -96,6 +96,18 @@
         self.assertEqual(aggregate['name'], body['name'])
         self.assertEqual(aggregate['availability_zone'],
                          body['availability_zone'])
+        self.assertEqual({}, body["metadata"])
+
+        # set the metadata of the aggregate
+        meta = {"key": "value"}
+        resp, body = self.client.set_metadata(aggregate['id'], meta)
+        self.assertEqual(200, resp.status)
+        self.assertEqual(meta, body["metadata"])
+
+        # verify the metadata has been set
+        resp, body = self.client.get_aggregate(aggregate['id'])
+        self.assertEqual(200, resp.status)
+        self.assertEqual(meta, body["metadata"])
 
     @attr(type='gate')
     def test_aggregate_create_update_with_az(self):
diff --git a/tempest/services/compute/json/aggregates_client.py b/tempest/services/compute/json/aggregates_client.py
index 75ce9ff..b7c6bf1 100644
--- a/tempest/services/compute/json/aggregates_client.py
+++ b/tempest/services/compute/json/aggregates_client.py
@@ -97,3 +97,14 @@
                                post_body, self.headers)
         body = json.loads(body)
         return resp, body['aggregate']
+
+    def set_metadata(self, aggregate_id, meta):
+        """Replaces the aggregate's existing metadata with new metadata."""
+        post_body = {
+            'metadata': meta,
+        }
+        post_body = json.dumps({'set_metadata': post_body})
+        resp, body = self.post('os-aggregates/%s/action' % aggregate_id,
+                               post_body, self.headers)
+        body = json.loads(body)
+        return resp, body['aggregate']
diff --git a/tempest/services/compute/xml/aggregates_client.py b/tempest/services/compute/xml/aggregates_client.py
index 8ef0af6..5faaff5 100644
--- a/tempest/services/compute/xml/aggregates_client.py
+++ b/tempest/services/compute/xml/aggregates_client.py
@@ -21,6 +21,7 @@
 from tempest import exceptions
 from tempest.services.compute.xml.common import Document
 from tempest.services.compute.xml.common import Element
+from tempest.services.compute.xml.common import Text
 from tempest.services.compute.xml.common import xml_to_json
 
 
@@ -112,3 +113,18 @@
                                self.headers)
         aggregate = self._format_aggregate(etree.fromstring(body))
         return resp, aggregate
+
+    def set_metadata(self, aggregate_id, meta):
+        """Replaces the aggregate's existing metadata with new metadata."""
+        post_body = Element("set_metadata")
+        metadata = Element("metadata")
+        post_body.append(metadata)
+        for k, v in meta.items():
+            meta = Element(k)
+            meta.append(Text(v))
+            metadata.append(meta)
+        resp, body = self.post('os-aggregates/%s/action' % aggregate_id,
+                               str(Document(post_body)),
+                               self.headers)
+        aggregate = self._format_aggregate(etree.fromstring(body))
+        return resp, aggregate