diff --git a/tacker/nfvo/drivers/vim/openstack_driver.py b/tacker/nfvo/drivers/vim/openstack_driver.py
index f04e25e74..c097a5648 100644
--- a/tacker/nfvo/drivers/vim/openstack_driver.py
+++ b/tacker/nfvo/drivers/vim/openstack_driver.py
@@ -16,6 +16,7 @@
 
 import os
 
+from keystoneclient import exceptions
 from oslo_config import cfg
 
 from tacker.common import log
@@ -95,12 +96,7 @@ class OpenStack_Driver(abstract_vim_driver.VimAbstractDriver):
         return keystone_version
 
     def _initialize_keystone(self, version, auth):
-        try:
-            ks_client = self.keystone.initialize_client(version=version,
-                                                        **auth)
-        except Exception as e:
-            LOG.error(_('VIM authentication failed'))
-            raise nfvo.VimUnauthorizedException(message=e.message)
+        ks_client = self.keystone.initialize_client(version=version, **auth)
         return ks_client
 
     def _find_regions(self, ks_client):
@@ -111,14 +107,12 @@ class OpenStack_Driver(abstract_vim_driver.VimAbstractDriver):
                 if service.type == 'orchestration':
                     heat_service_id = service.id
             endpoints_list = ks_client.endpoints.list()
-            region_list = [endpoint.region for endpoint in endpoints_list if
-                           endpoint.service_id == heat_service_id]
+            region_list = [endpoint.region for endpoint in
+                           endpoints_list if endpoint.service_id ==
+                           heat_service_id]
         else:
             region_info = ks_client.regions.list()
             region_list = [region.id for region in region_info]
-        if not region_list:
-            LOG.info(_('Unable to find VIM regions'))
-            return
         return region_list
 
     def discover_placement_attr(self, vim_obj, ks_client):
@@ -126,7 +120,11 @@ class OpenStack_Driver(abstract_vim_driver.VimAbstractDriver):
 
         Attributes can include regions, AZ.
         """
-        regions_list = self._find_regions(ks_client)
+        try:
+            regions_list = self._find_regions(ks_client)
+        except exceptions.Unauthorized as e:
+            LOG.warn(_("Authorization failed for user"))
+            raise nfvo.VimUnauthorizedException(message=e.message)
         vim_obj['placement_attr'] = {'regions': regions_list}
         return vim_obj
 
diff --git a/tacker/tests/unit/vm/nfvo/drivers/vim/test_openstack_driver.py b/tacker/tests/unit/vm/nfvo/drivers/vim/test_openstack_driver.py
index 48da8a557..815a3d520 100644
--- a/tacker/tests/unit/vm/nfvo/drivers/vim/test_openstack_driver.py
+++ b/tacker/tests/unit/vm/nfvo/drivers/vim/test_openstack_driver.py
@@ -13,9 +13,11 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from keystoneclient import exceptions
 import mock
 from oslo_config import cfg
 
+from tacker.extensions import nfvo
 from tacker.nfvo.drivers.vim import openstack_driver
 from tacker.tests.unit import base
 from tacker.tests.unit.db import utils
@@ -115,3 +117,15 @@ class TestOpenstack_Driver(base.TestCase):
         mock_os_path.return_value = file_path
         self.openstack_driver.deregister_vim(vim_id)
         mock_os_remove.assert_called_once_with(file_path)
+
+    def test_register_vim_invalid_credentials(self):
+        attrs = {'regions.list.side_effect': exceptions.Unauthorized}
+        keystone_version = 'v3'
+        mock_ks_client = mock.Mock(version=keystone_version, **attrs)
+        self.keystone.get_version.return_value = keystone_version
+        self.keystone.initialize_client.return_value = mock_ks_client
+        self.assertRaises(nfvo.VimUnauthorizedException,
+                          self.openstack_driver.register_vim, self.vim_obj)
+        mock_ks_client.regions.list.assert_called_once_with()
+        self.keystone.initialize_client.assert_called_once_with(
+            version=keystone_version, **self.auth_obj)
diff --git a/tacker/vm/keystone.py b/tacker/vm/keystone.py
index 438b45f98..435a11f19 100644
--- a/tacker/vm/keystone.py
+++ b/tacker/vm/keystone.py
@@ -58,13 +58,8 @@ class Keystone(object):
             from keystoneclient.v3 import client
             auth_plugin = identity.v3.Password(**kwargs)
         ses = self.get_session(auth_plugin=auth_plugin)
-        try:
-            cli = client.Client(session=ses)
-            return cli
-        except (exceptions.AuthorizationFailure,
-                exceptions.Unauthorized):
-            LOG.warn(_("Authorization failed for user"))
-            raise
+        cli = client.Client(session=ses)
+        return cli
 
     @staticmethod
     def create_key_dir(path):