diff --git a/patrole_tempest_plugin/rbac_exceptions.py b/patrole_tempest_plugin/rbac_exceptions.py
index c6165ff..ee42e19 100644
--- a/patrole_tempest_plugin/rbac_exceptions.py
+++ b/patrole_tempest_plugin/rbac_exceptions.py
@@ -26,3 +26,7 @@
 
 class RbacOverPermission (exceptions.TempestException):
     message = "Action performed that should not be permitted"
+
+
+class RbacInvalidService (exceptions.TempestException):
+    message = "Attempted to test an invalid service"
diff --git a/patrole_tempest_plugin/rbac_policy_parser.py b/patrole_tempest_plugin/rbac_policy_parser.py
index 045a9f8..9926613 100644
--- a/patrole_tempest_plugin/rbac_policy_parser.py
+++ b/patrole_tempest_plugin/rbac_policy_parser.py
@@ -20,6 +20,8 @@
 from oslo_policy import generator
 from oslo_policy import policy
 
+from tempest.common import credentials_factory as credentials
+
 from patrole_tempest_plugin import rbac_exceptions
 
 LOG = logging.getLogger(__name__)
@@ -57,7 +59,17 @@
         :param service: type string
         :param path: type string
         """
-        service = service.lower().strip()
+        # First check if the service is valid
+        service = service.lower().strip() if service else None
+        self.admin_mgr = credentials.AdminManager()
+        services = self.admin_mgr.identity_services_v3_client.\
+            list_services()['services']
+        service_names = [s['name'] for s in services]
+        if not service or not any(service in name for name in service_names):
+            LOG.debug(str(service) + " is NOT a valid service.")
+            raise rbac_exceptions.RbacInvalidService
+
+        # Use default path if no path provided
         if path is None:
             self.path = os.path.join('/etc', service, 'policy.json')
         else:
@@ -65,7 +77,7 @@
 
         policy_data = "{}"
 
-        # First check whether policy file exists.
+        # Check whether policy file exists.
         if os.path.isfile(self.path):
             policy_data = open(self.path, 'r').read()
         # Otherwise use oslo_policy to fetch the rules for provided service.
diff --git a/patrole_tempest_plugin/rbac_rule_validation.py b/patrole_tempest_plugin/rbac_rule_validation.py
index 36784b7..284d8f0 100644
--- a/patrole_tempest_plugin/rbac_rule_validation.py
+++ b/patrole_tempest_plugin/rbac_rule_validation.py
@@ -41,6 +41,12 @@
 
             try:
                 func(*args)
+            except rbac_exceptions.RbacInvalidService as e:
+                    msg = ("%s is not a valid service." % service)
+                    LOG.error(msg)
+                    raise exceptions.NotFound(
+                        "%s RbacInvalidService was: %s" %
+                        (msg, e))
             except exceptions.Forbidden as e:
                 if allowed:
                     msg = ("Role %s was not allowed to perform %s." %
diff --git a/patrole_tempest_plugin/tests/unit/test_rbac_policy_parser.py b/patrole_tempest_plugin/tests/unit/test_rbac_policy_parser.py
index 35aaa82..edc63b8 100644
--- a/patrole_tempest_plugin/tests/unit/test_rbac_policy_parser.py
+++ b/patrole_tempest_plugin/tests/unit/test_rbac_policy_parser.py
@@ -19,6 +19,7 @@
 from tempest import config
 from tempest.tests import base
 
+from patrole_tempest_plugin import rbac_exceptions
 from patrole_tempest_plugin import rbac_policy_parser
 
 CONF = config.CONF
@@ -28,6 +29,8 @@
 
     def setUp(self):
         super(RbacPolicyTest, self).setUp()
+        self.mock_admin_mgr = mock.patch.object(
+            rbac_policy_parser, 'credentials').start()
 
         current_directory = os.path.dirname(os.path.realpath(__file__))
         self.custom_policy_file = os.path.join(current_directory,
@@ -42,6 +45,35 @@
         self.tenant_policy_file = os.path.join(current_directory,
                                                'resources',
                                                'tenant_rbac_policy.json')
+        services = {
+            'services': [
+                {'name': 'cinder', 'links': 'link', 'enabled': True,
+                 'type': 'volume', 'id': 'id',
+                 'description': 'description'},
+                {'name': 'glance', 'links': 'link', 'enabled': True,
+                 'type': 'image', 'id': 'id',
+                 'description': 'description'},
+                {'name': 'nova', 'links': 'link', 'enabled': True,
+                 'type': 'compute', 'id': 'id',
+                 'description': 'description'},
+                {'name': 'keystone', 'links': 'link', 'enabled': True,
+                 'type': 'identity', 'id': 'id',
+                 'description': 'description'},
+                {'name': 'heat', 'links': 'link', 'enabled': True,
+                 'type': 'orchestration', 'id': 'id',
+                 'description': 'description'},
+                {'name': 'neutron', 'links': 'link', 'enabled': True,
+                 'type': 'networking', 'id': 'id',
+                 'description': 'description'},
+                {'name': 'test', 'links': 'link', 'enabled': True,
+                 'type': 'unit_test', 'id': 'id',
+                 'description': 'description'}
+            ]
+        }
+
+        self.mock_admin_mgr.AdminManager.return_value.\
+            identity_services_v3_client.list_services.return_value = \
+            services
 
     @mock.patch.object(rbac_policy_parser, 'LOG', autospec=True)
     def test_custom_policy(self, m_log):
@@ -203,3 +235,33 @@
                 mock_try_rule.assert_called_once_with(
                     rule, expected_target, expected_access_data, mock.ANY)
                 mock_try_rule.reset_mock()
+
+    @mock.patch.object(rbac_policy_parser, 'LOG', autospec=True)
+    def test_invalid_service_raises_exception(self, m_log):
+        test_tenant_id = mock.sentinel.tenant_id
+        test_user_id = mock.sentinel.user_id
+        service = 'invalid_service'
+
+        self.assertRaises(rbac_exceptions.RbacInvalidService,
+                          rbac_policy_parser.RbacPolicyParser,
+                          test_tenant_id,
+                          test_user_id,
+                          service)
+
+        m_log.debug.assert_called_once_with(
+            "{0} is NOT a valid service.".format(str(service)))
+
+    @mock.patch.object(rbac_policy_parser, 'LOG', autospec=True)
+    def test_service_is_none_raises_exception(self, m_log):
+        test_tenant_id = mock.sentinel.tenant_id
+        test_user_id = mock.sentinel.user_id
+        service = None
+
+        self.assertRaises(rbac_exceptions.RbacInvalidService,
+                          rbac_policy_parser.RbacPolicyParser,
+                          test_tenant_id,
+                          test_user_id,
+                          service)
+
+        m_log.debug.assert_called_once_with(
+            "{0} is NOT a valid service.".format(str(service)))