diff --git a/releasenotes/notes/plugin-service-client-registration-00b19a2dd4935ba0.yaml b/releasenotes/notes/plugin-service-client-registration-00b19a2dd4935ba0.yaml
new file mode 100644
index 0000000..64f729a
--- /dev/null
+++ b/releasenotes/notes/plugin-service-client-registration-00b19a2dd4935ba0.yaml
@@ -0,0 +1,12 @@
+---
+features:
+  - A new optional interface `TempestPlugin.get_service_clients`
+    is available to plugins. It allows them to declare
+    any service client they implement. For now this is used by
+    tempest only, for auto-registration of service clients
+    in the new class `ServiceClients`.
+  - A new singleton class `clients.ClientsRegistry` is
+    available. It holds the service clients registration data
+    from all plugins. It is used by `ServiceClients` for
+    auto-registration of the service clients implemented
+    in plugins.
diff --git a/tempest/lib/exceptions.py b/tempest/lib/exceptions.py
index 5ca78f9..de2d713 100644
--- a/tempest/lib/exceptions.py
+++ b/tempest/lib/exceptions.py
@@ -229,3 +229,13 @@
 
 class UnknownServiceClient(TempestException):
     message = "Service clients named %(services)s are not known"
+
+
+class ServiceClientRegistrationException(TempestException):
+    message = ("Error registering module %(name)s in path %(module_path)s, "
+               "with service %(service_version)s and clients "
+               "%(client_names)s: %(detailed_error)s")
+
+
+class PluginRegistrationException(TempestException):
+    message = "Error registering plugin %(name)s: %(detailed_error)s"
diff --git a/tempest/lib/services/clients.py b/tempest/lib/services/clients.py
new file mode 100644
index 0000000..8054e62
--- /dev/null
+++ b/tempest/lib/services/clients.py
@@ -0,0 +1,36 @@
+# Copyright (c) 2016 Hewlett-Packard Enterprise Development Company, L.P.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from tempest.lib.common.utils import misc
+from tempest.lib import exceptions
+
+
+@misc.singleton
+class ClientsRegistry(object):
+    """Registry of all service clients available from plugins"""
+
+    def __init__(self):
+        self._service_clients = {}
+
+    def register_service_client(self, plugin_name, service_client_data):
+        if plugin_name in self._service_clients:
+            detailed_error = 'Clients for plugin %s already registered'
+            raise exceptions.PluginRegistrationException(
+                name=plugin_name,
+                detailed_error=detailed_error % plugin_name)
+        self._service_clients[plugin_name] = service_client_data
+
+    def get_service_clients(self):
+        return self._service_clients
diff --git a/tempest/service_clients.py b/tempest/service_clients.py
index 252ebf4..d0daa2b 100644
--- a/tempest/service_clients.py
+++ b/tempest/service_clients.py
@@ -17,9 +17,13 @@
 import copy
 import importlib
 import inspect
+import logging
 
 from tempest.lib import auth
 from tempest.lib import exceptions
+from tempest.lib.services import clients
+
+LOG = logging.getLogger(__name__)
 
 
 def tempest_modules():
@@ -33,9 +37,48 @@
 
 
 def available_modules():
-    """List of service client modules available in Tempest and plugins"""
-    # TODO(andreaf) For now this returns only tempest_modules
-    return tempest_modules()
+    """List of service client modules available in Tempest and plugins
+
+    The list of available modules can be used for automatic configuration.
+
+    :raise PluginRegistrationException: if a plugin exposes a service_version
+        already defined by Tempest or another plugin.
+
+    Examples:
+
+        >>> from tempest import config
+        >>> params = {}
+        >>> for service_version in available_modules():
+        >>>     service = service_version.split('.')[0]
+        >>>     params[service] = config.service_client_config(service)
+        >>> service_clients = ServiceClients(creds, identity_uri,
+        >>>                                  client_parameters=params)
+    """
+    extra_service_versions = set([])
+    plugin_services = clients.ClientsRegistry().get_service_clients()
+    for plugin_name in plugin_services:
+        plug_service_versions = set([x['service_version'] for x in
+                                     plugin_services[plugin_name]])
+        # If a plugin exposes a duplicate service_version raise an exception
+        if plug_service_versions:
+            if not plug_service_versions.isdisjoint(extra_service_versions):
+                detailed_error = (
+                    'Plugin %s is trying to register a service %s already '
+                    'claimed by another one' % (plugin_name,
+                                                extra_service_versions &
+                                                plug_service_versions))
+                raise exceptions.PluginRegistrationException(
+                    name=plugin_name, detailed_error=detailed_error)
+            if not plug_service_versions.isdisjoint(tempest_modules()):
+                detailed_error = (
+                    'Plugin %s is trying to register a service %s already '
+                    'claimed by a Tempest one' % (plugin_name,
+                                                  tempest_modules() &
+                                                  plug_service_versions))
+                raise exceptions.PluginRegistrationException(
+                    name=plugin_name, detailed_error=detailed_error)
+        extra_service_versions |= plug_service_versions
+    return tempest_modules() | extra_service_versions
 
 
 class ClientsFactory(object):
@@ -49,8 +92,6 @@
     ClientsFactory can be used directly, or consumed via the `ServiceClients`
     class, which manages the authorization part.
     """
-    # TODO(andreaf) This version includes ClientsFactory but it does not
-    # use it yet in ServiceClients
 
     def __init__(self, module_path, client_names, auth_provider, **kwargs):
         """Initialises the client factory
@@ -206,6 +247,7 @@
             >>> client_parameters['service_y'] = params_service_y
 
         """
+        self._registered_services = set([])
         self.credentials = credentials
         self.identity_uri = identity_uri
         if not identity_uri:
@@ -247,6 +289,84 @@
             raise exceptions.UnknownServiceClient(
                 services=list(client_parameters.keys()))
 
+        # Register service clients from plugins
+        clients_registry = clients.ClientsRegistry()
+        plugin_service_clients = clients_registry.get_service_clients()
+        for plugin in plugin_service_clients:
+            service_clients = plugin_service_clients[plugin]
+            # Each plugin returns a list of service client parameters
+            for service_client in service_clients:
+                # NOTE(andreaf) If a plugin cannot register, stop the
+                # registration process, log some details to help
+                # troubleshooting, and re-raise
+                try:
+                    self.register_service_client_module(**service_client)
+                except Exception:
+                    LOG.exception(
+                        'Failed to register service client from plugin %s '
+                        'with parameters %s' % (plugin, service_client))
+                    raise
+
+    def register_service_client_module(self, name, service_version,
+                                       module_path, client_names, **kwargs):
+        """Register a service client module
+
+        Initiates a client factory for the specified module, using this
+        class auth_provider, and accessible via a `name` attribute in the
+        service client.
+
+        :param name: Name used to access the client
+        :param service_version: Name of the service complete with version.
+            Used to track registered services. When a plugin implements it,
+            it can be used by other plugins to obtain their configuration.
+        :param module_path: Path to module that includes all service clients.
+            All service client classes must be exposed by a single module.
+            If they are separated in different modules, defining __all__
+            in the root module can help, similar to what is done by service
+            clients in tempest.
+        :param client_names: List or set of names of service client classes.
+        :param kwargs: Extra optional parameters to be passed to all clients.
+            ServiceClient provides defaults for region, dscv, ca_certs and
+            trace_requests.
+        :raise ServiceClientRegistrationException: if the provided name is
+            already in use or if service_version is already registered.
+        :raise ImportError: if module_path cannot be imported.
+        """
+        if hasattr(self, name):
+            using_name = getattr(self, name)
+            detailed_error = 'Module name already in use: %s' % using_name
+            raise exceptions.ServiceClientRegistrationException(
+                name=name, service_version=service_version,
+                module_path=module_path, client_names=client_names,
+                detailed_error=detailed_error)
+        if service_version in self.registered_services:
+            detailed_error = 'Service %s already registered.' % service_version
+            raise exceptions.ServiceClientRegistrationException(
+                name=name, service_version=service_version,
+                module_path=module_path, client_names=client_names,
+                detailed_error=detailed_error)
+        params = dict(region=self.region,
+                      disable_ssl_certificate_validation=self.dscv,
+                      ca_certs=self.ca_certs,
+                      trace_requests=self.trace_requests)
+        params.update(kwargs)
+        # Instantiate the client factory
+        _factory = ClientsFactory(module_path=module_path,
+                                  client_names=client_names,
+                                  auth_provider=self.auth_provider,
+                                  **params)
+        # Adds the client factory to the service_client
+        setattr(self, name, _factory)
+        # Add the name of the new service in self.SERVICES for discovery
+        self._registered_services.add(service_version)
+
+    @property
+    def registered_services(self):
+        # TODO(andreaf) For now add all Tempest services. to the list of
+        # registered service
+        _default_services = tempest_modules()
+        return self._registered_services | _default_services
+
     def _setup_parameters(self, parameters):
         """Setup default values for client parameters
 
diff --git a/tempest/test_discover/plugins.py b/tempest/test_discover/plugins.py
index d604b28..cfb0c7f 100644
--- a/tempest/test_discover/plugins.py
+++ b/tempest/test_discover/plugins.py
@@ -19,6 +19,7 @@
 import stevedore
 
 from tempest.lib.common.utils import misc
+from tempest.lib.services import clients
 
 LOG = logging.getLogger(__name__)
 
@@ -62,6 +63,54 @@
         """
         return []
 
+    def get_service_clients(self):
+        """Get a list of the service clients for registration
+
+        If the plugin implements service clients for one or more APIs, it
+        may return their details by this method for automatic registration
+        in any ServiceClients object instantiated by tests.
+        The default implementation returns an empty list.
+
+        :return list of dictionaries. Each element of the list represents
+            the service client for an API. Each dict must define all
+            parameters required for the invocation of
+            `service_clients.ServiceClients.register_service_client_module`.
+        :rtype: list
+
+        Example:
+
+            >>>  # Example implementation with one service client
+            >>>  myservice_config = config.service_client_config('myservice')
+            >>>  params = {
+            >>>     'name': 'myservice',
+            >>>     'service_version': 'myservice',
+            >>>     'module_path': 'myservice_tempest_tests.services',
+            >>>     'client_names': ['API1Client', 'API2Client'],
+            >>>  }
+            >>>  params.update(myservice_config)
+            >>> return [params]
+
+            >>>  # Example implementation with two service clients
+            >>>  foo1_config = config.service_client_config('foo')
+            >>>  params_foo1 = {
+            >>>     'name': 'foo_v1',
+            >>>     'service_version': 'foo.v1',
+            >>>     'module_path': 'bar_tempest_tests.services.foo.v1',
+            >>>     'client_names': ['API1Client', 'API2Client'],
+            >>>  }
+            >>>  params_foo1.update(foo_config)
+            >>>  foo2_config = config.service_client_config('foo')
+            >>>  params_foo2 = {
+            >>>     'name': 'foo_v2',
+            >>>     'service_version': 'foo.v2',
+            >>>     'module_path': 'bar_tempest_tests.services.foo.v2',
+            >>>     'client_names': ['API1Client', 'API2Client'],
+            >>>  }
+            >>>  params_foo2.update(foo2_config)
+            >>> return [params_foo1, params_foo2]
+        """
+        return []
+
 
 @misc.singleton
 class TempestTestPluginManager(object):
@@ -75,6 +124,7 @@
             'tempest.test_plugins', invoke_on_load=True,
             propagate_map_exceptions=True,
             on_load_failure_callback=self.failure_hook)
+        self._register_service_clients()
 
     @staticmethod
     def failure_hook(_, ep, err):
@@ -102,3 +152,13 @@
             if opt_list:
                 plugin_options.extend(opt_list)
         return plugin_options
+
+    def _register_service_clients(self):
+        registry = clients.ClientsRegistry()
+        for plug in self.ext_plugins:
+            try:
+                registry.register_service_client(
+                    plug.name, plug.obj.get_service_clients())
+            except Exception:
+                LOG.exception('Plugin %s raised an exception trying to run '
+                              'get_service_clients' % plug.name)
diff --git a/tempest/tests/fake_tempest_plugin.py b/tempest/tests/fake_tempest_plugin.py
index f718d0b..56aae1e 100644
--- a/tempest/tests/fake_tempest_plugin.py
+++ b/tempest/tests/fake_tempest_plugin.py
@@ -18,6 +18,7 @@
 
 class FakePlugin(plugins.TempestPlugin):
     expected_load_test = ["my/test/path", "/home/dir"]
+    expected_service_clients = [{'foo': 'bar'}]
 
     def load_tests(self):
         return self.expected_load_test
@@ -28,6 +29,9 @@
     def get_opt_lists(self):
         return []
 
+    def get_service_clients(self):
+        return self.expected_service_clients
+
 
 class FakeStevedoreObj(object):
     obj = FakePlugin()
@@ -38,3 +42,26 @@
 
     def __init__(self, name='Test1'):
         self._name = name
+
+
+class FakePluginNoServiceClients(plugins.TempestPlugin):
+
+    def load_tests(self):
+        return []
+
+    def register_opts(self, conf):
+        return
+
+    def get_opt_lists(self):
+        return []
+
+
+class FakeStevedoreObjNoServiceClients(object):
+    obj = FakePluginNoServiceClients()
+
+    @property
+    def name(self):
+        return self._name
+
+    def __init__(self, name='Test2'):
+        self._name = name
diff --git a/tempest/tests/test_service_clients.py b/tempest/tests/test_service_clients.py
index 26cc93f..befed68 100644
--- a/tempest/tests/test_service_clients.py
+++ b/tempest/tests/test_service_clients.py
@@ -263,3 +263,82 @@
         for _key in _params.keys():
             self.assertEqual(expected_params[_key],
                              _params[_key])
+
+    def test_register_service_client_module(self):
+        factory_mock = self.useFixture(fixtures.MockPatch(
+            'tempest.service_clients.ClientsFactory')).mock
+        expected_params = {'fake_param1': 'fake_value1',
+                           'fake_param2': 'fake_value2'}
+        _manager = self._get_manager(init_region='fake_region_default')
+        _manager.register_service_client_module(
+            name='fake_module',
+            service_version='fake_service',
+            module_path='fake.path.to.module',
+            client_names=[],
+            **expected_params)
+        self.assertThat(_manager, has_attribute('fake_module'))
+        # Assert called once, without check for exact parameters
+        self.assertTrue(factory_mock.called)
+        self.assertEqual(1, factory_mock.call_count)
+        # Assert expected params are in with their values
+        actual_kwargs = factory_mock.call_args[1]
+        self.assertIn('region', actual_kwargs)
+        self.assertEqual('fake_region_default', actual_kwargs['region'])
+        for param in expected_params:
+            self.assertIn(param, actual_kwargs)
+            self.assertEqual(expected_params[param], actual_kwargs[param])
+        # Assert the new service is registered
+        self.assertIn('fake_service', _manager._registered_services)
+
+    def test_register_service_client_module_override_default(self):
+        factory_mock = self.useFixture(fixtures.MockPatch(
+            'tempest.service_clients.ClientsFactory')).mock
+        new_region = 'new_region'
+        expected_params = {'fake_param1': 'fake_value1',
+                           'fake_param2': 'fake_value2',
+                           'region': new_region}
+        _manager = self._get_manager(init_region='fake_region_default')
+        _manager.register_service_client_module(
+            name='fake_module',
+            service_version='fake_service',
+            module_path='fake.path.to.module',
+            client_names=[],
+            **expected_params)
+        self.assertThat(_manager, has_attribute('fake_module'))
+        # Assert called once, without check for exact parameters
+        self.assertTrue(factory_mock.called)
+        self.assertEqual(1, factory_mock.call_count)
+        # Assert expected params are in with their values
+        actual_kwargs = factory_mock.call_args[1]
+        self.assertIn('region', actual_kwargs)
+        self.assertEqual(new_region, actual_kwargs['region'])
+        for param in expected_params:
+            self.assertIn(param, actual_kwargs)
+            self.assertEqual(expected_params[param], actual_kwargs[param])
+        # Assert the new service is registered
+        self.assertIn('fake_service', _manager._registered_services)
+
+    def test_register_service_client_module_duplicate_name(self):
+        self.useFixture(fixtures.MockPatch(
+            'tempest.service_clients.ClientsFactory'))
+        _manager = self._get_manager()
+        name_owner = 'this_is_a_string'
+        setattr(_manager, 'fake_module', name_owner)
+        expected_error = '.*' + name_owner
+        with testtools.ExpectedException(
+                exceptions.ServiceClientRegistrationException, expected_error):
+            _manager.register_service_client_module(
+                name='fake_module', module_path='fake.path.to.module',
+                service_version='fake_service', client_names=[])
+
+    def test_register_service_client_module_duplicate_service(self):
+        self.useFixture(fixtures.MockPatch(
+            'tempest.service_clients.ClientsFactory'))
+        _manager = self._get_manager()
+        duplicate_service = 'fake_service1'
+        expected_error = '.*' + duplicate_service
+        with testtools.ExpectedException(
+                exceptions.ServiceClientRegistrationException, expected_error):
+            _manager.register_service_client_module(
+                name='fake_module', module_path='fake.path.to.module',
+                service_version=duplicate_service, client_names=[])
diff --git a/tempest/tests/test_tempest_plugin.py b/tempest/tests/test_tempest_plugin.py
index c07e98c..dd50125 100644
--- a/tempest/tests/test_tempest_plugin.py
+++ b/tempest/tests/test_tempest_plugin.py
@@ -13,6 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from tempest.lib.services import clients
 from tempest.test_discover import plugins
 from tempest.tests import base
 from tempest.tests import fake_tempest_plugin as fake_plugin
@@ -42,3 +43,39 @@
                          result['fake01'])
         self.assertEqual(fake_plugin.FakePlugin.expected_load_test,
                          result['fake02'])
+
+    def test__register_service_clients_with_one_plugin(self):
+        registry = clients.ClientsRegistry()
+        manager = plugins.TempestTestPluginManager()
+        fake_obj = fake_plugin.FakeStevedoreObj()
+        manager.ext_plugins = [fake_obj]
+        manager._register_service_clients()
+        expected_result = fake_plugin.FakePlugin.expected_service_clients
+        registered_clients = registry.get_service_clients()
+        self.assertIn(fake_obj.name, registered_clients)
+        self.assertEqual(expected_result, registered_clients[fake_obj.name])
+
+    def test__get_service_clients_with_two_plugins(self):
+        registry = clients.ClientsRegistry()
+        manager = plugins.TempestTestPluginManager()
+        obj1 = fake_plugin.FakeStevedoreObj('fake01')
+        obj2 = fake_plugin.FakeStevedoreObj('fake02')
+        manager.ext_plugins = [obj1, obj2]
+        manager._register_service_clients()
+        expected_result = fake_plugin.FakePlugin.expected_service_clients
+        registered_clients = registry.get_service_clients()
+        self.assertIn('fake01', registered_clients)
+        self.assertIn('fake02', registered_clients)
+        self.assertEqual(expected_result, registered_clients['fake01'])
+        self.assertEqual(expected_result, registered_clients['fake02'])
+
+    def test__register_service_clients_one_plugin_no_service_clients(self):
+        registry = clients.ClientsRegistry()
+        manager = plugins.TempestTestPluginManager()
+        fake_obj = fake_plugin.FakeStevedoreObjNoServiceClients()
+        manager.ext_plugins = [fake_obj]
+        manager._register_service_clients()
+        expected_result = []
+        registered_clients = registry.get_service_clients()
+        self.assertIn(fake_obj.name, registered_clients)
+        self.assertEqual(expected_result, registered_clients[fake_obj.name])