diff --git a/troveclient/tests/fakes.py b/troveclient/tests/fakes.py
index a2791059..90345312 100644
--- a/troveclient/tests/fakes.py
+++ b/troveclient/tests/fakes.py
@@ -270,6 +270,9 @@ class FakeHTTPClient(base_client.HTTPClient):
                 assert_has_keys(instance, required=['volume', 'flavorRef'])
         return (202, {}, self.get_clusters_cls_1234()[2])
 
+    def post_clusters_cls_1234(self, body, **kw):
+        return (202, {}, None)
+
     def post_instances_1234_action(self, **kw):
         return (202, {}, None)
 
diff --git a/troveclient/tests/test_v1_shell.py b/troveclient/tests/test_v1_shell.py
index 72a52a0b..9ebcd5bb 100644
--- a/troveclient/tests/test_v1_shell.py
+++ b/troveclient/tests/test_v1_shell.py
@@ -13,10 +13,10 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import fixtures
-import mock
 import six
 
+import fixtures
+import mock
 import troveclient.client
 from troveclient import exceptions
 import troveclient.shell
@@ -26,6 +26,7 @@ import troveclient.v1.shell
 
 
 class ShellFixture(fixtures.Fixture):
+
     def setUp(self):
         super(ShellFixture, self).setUp()
         self.shell = troveclient.shell.OpenStackTroveShell()
@@ -232,6 +233,18 @@ class ShellTest(utils.TestCase):
             exceptions.CommandError, 'flavor is required',
             self.run_command, cmd)
 
+    def test_cluster_grow(self):
+        cmd = ('cluster-grow cls-1234 '
+               '--instance flavor=2,volume=2 '
+               '--instance flavor=2,volume=1')
+        self.run_command(cmd)
+        self.assert_called('POST', '/clusters/cls-1234')
+
+    def test_cluster_shrink(self):
+        cmd = ('cluster-shrink cls-1234 1234')
+        self.run_command(cmd)
+        self.assert_called('POST', '/clusters/cls-1234')
+
     def test_datastore_list(self):
         self.run_command('datastore-list')
         self.assert_called('GET', '/datastores')
diff --git a/troveclient/v1/clusters.py b/troveclient/v1/clusters.py
index dc9c2f05..bf207221 100644
--- a/troveclient/v1/clusters.py
+++ b/troveclient/v1/clusters.py
@@ -70,6 +70,15 @@ class Clusters(base.ManagerWithFind):
         resp, body = self.api.client.delete(url)
         common.check_for_exceptions(resp, body, url)
 
+    def _action(self, cluster, body):
+        """Perform a cluster "action" -- grow/shrink/etc."""
+        url = "/clusters/%s" % base.getid(cluster)
+        resp, body = self.api.client.post(url, body=body)
+        common.check_for_exceptions(resp, body, url)
+        if body:
+            return self.resource_class(self, body['cluster'], loaded=True)
+        return body
+
     def add_shard(self, cluster):
         """Adds a shard to the specified cluster.
 
@@ -83,6 +92,24 @@ class Clusters(base.ManagerWithFind):
             return self.resource_class(self, body, loaded=True)
         return body
 
+    def grow(self, cluster, instances=None):
+        """Grow a cluster.
+
+        :param cluster:     The cluster to grow
+        :param instances:   List of instances to add
+        """
+        body = {"grow": instances}
+        return self._action(cluster, body)
+
+    def shrink(self, cluster, instances=None):
+        """Shrink a cluster.
+
+        :param cluster:     The cluster to shrink
+        :param instances:   List of instances to drop
+        """
+        body = {"shrink": instances}
+        return self._action(cluster, body)
+
 
 class ClusterStatus(object):
 
diff --git a/troveclient/v1/shell.py b/troveclient/v1/shell.py
index 3dfa5f77..38b110d5 100644
--- a/troveclient/v1/shell.py
+++ b/troveclient/v1/shell.py
@@ -253,6 +253,58 @@ def do_cluster_instances(cs, args):
         obj_is_dict=True)
 
 
+@utils.arg('--instance',
+           metavar="<name=name,flavor=flavor_name_or_id,volume=volume>",
+           action='append',
+           dest='instances',
+           default=[],
+           help="Add an instance to the cluster. Specify "
+                "multiple times to create multiple instances.")
+@utils.arg('cluster', metavar='<cluster>', help='ID or name of the cluster.')
+@utils.service_type('database')
+def do_cluster_grow(cs, args):
+    """Adds more instances to a cluster."""
+    cluster = _find_cluster(cs, args.cluster)
+    instances = []
+    for instance_str in args.instances:
+        instance_info = {}
+        for z in instance_str.split(","):
+            for (k, v) in [z.split("=", 1)[:2]]:
+                if k == "name":
+                    instance_info[k] = v
+                elif k == "flavor":
+                    flavor_id = _find_flavor(cs, v).id
+                    instance_info["flavorRef"] = str(flavor_id)
+                elif k == "volume":
+                    instance_info["volume"] = {"size": v}
+                else:
+                    instance_info[k] = v
+        if not instance_info.get('flavorRef'):
+            raise exceptions.CommandError(
+                'flavor is required. '
+                'Instance arguments must be of the form '
+                '--instance <flavor=flavor_name_or_id,volume=volume,data=data>'
+            )
+        instances.append(instance_info)
+    cs.clusters.grow(cluster, instances=instances)
+
+
+@utils.arg('cluster', metavar='<cluster>', help='ID or name of the cluster.')
+@utils.arg('instances',
+           nargs='+',
+           metavar='<instance>',
+           default=[],
+           help="Drop instance(s) from the cluster. Specify "
+                "multiple ids to drop multiple instances.")
+@utils.service_type('database')
+def do_cluster_shrink(cs, args):
+    """Drops instances from a cluster."""
+    cluster = _find_cluster(cs, args.cluster)
+    instances = [{'id': _find_instance(cs, instance).id}
+                 for instance in args.instances]
+    cs.clusters.shrink(cluster, instances=instances)
+
+
 @utils.arg('instance', metavar='<instance>',
            help='ID or name  of the instance.')
 @utils.service_type('database')