diff --git a/oslo_config/fixture.py b/oslo_config/fixture.py
index 02d570d9..bb0f287d 100644
--- a/oslo_config/fixture.py
+++ b/oslo_config/fixture.py
@@ -116,3 +116,27 @@ class Config(fixtures.Fixture):
         """
         for opt in opts:
             self.register_cli_opt(opt, group=group)
+
+    def load_raw_values(self, group=None, **kwargs):
+        """Load raw values into the configuration without registering them.
+
+        This method adds a series of parameters into the current config
+        instance, as if they had been loaded by a ConfigParser. This method
+        does not require that you register the configuration options first,
+        however the values loaded will not be accessible until you do.
+        """
+
+        # Make sure the namespace exists for our tests.
+        if not self.conf._namespace:
+            self.conf.__call__(args=[])
+
+        # Default out the group name
+        group = 'DEFAULT' if not group else group
+
+        raw_config = dict()
+        raw_config[group] = dict()
+        for key, value in six.iteritems(kwargs):
+            # Parsed values are an array of raw strings.
+            raw_config[group][key] = [str(value)]
+
+        self.conf._namespace._add_parsed_config_file(raw_config, raw_config)
diff --git a/oslo_config/tests/test_fixture.py b/oslo_config/tests/test_fixture.py
index 6d8b2a7b..671bea98 100644
--- a/oslo_config/tests/test_fixture.py
+++ b/oslo_config/tests/test_fixture.py
@@ -85,3 +85,33 @@ class ConfigTestCase(base.BaseTestCase):
                          opt.default)
         self.config_fixture.cleanUp()
         self.assertRaises(cfg.NoSuchOptError, conf.get, 'new_test_opt')
+
+    def test_load_raw_values(self):
+        self.config_fixture.load_raw_values(first_test_opt='loaded_value_1',
+                                            second_test_opt='loaded_value_2')
+
+        # Must not be registered.
+        self.assertRaises(cfg.NoSuchOptError, conf.get, 'first_test_opt')
+        self.assertRaises(cfg.NoSuchOptError, conf.get, 'second_test_opt')
+
+        opt1 = cfg.StrOpt('first_test_opt', default='initial_value_1')
+        opt2 = cfg.StrOpt('second_test_opt', default='initial_value_2')
+
+        self.config_fixture.register_opt(opt1)
+        self.config_fixture.register_opt(opt2)
+
+        self.assertEqual(conf.first_test_opt, 'loaded_value_1')
+        self.assertEqual(conf.second_test_opt, 'loaded_value_2')
+
+        # Cleanup.
+        self.config_fixture.cleanUp()
+
+        # Must no longer be registered.
+        self.assertRaises(cfg.NoSuchOptError, conf.get, 'first_test_opt')
+        self.assertRaises(cfg.NoSuchOptError, conf.get, 'second_test_opt')
+
+        # Even when registered, must be default.
+        self.config_fixture.register_opt(opt1)
+        self.config_fixture.register_opt(opt2)
+        self.assertEqual(conf.first_test_opt, 'initial_value_1')
+        self.assertEqual(conf.second_test_opt, 'initial_value_2')