diff --git a/releasenotes/notes/dreprecate_client_parameters-cb8d069e62957f7e.yaml b/releasenotes/notes/dreprecate_client_parameters-cb8d069e62957f7e.yaml
new file mode 100644
index 0000000..4081f6a
--- /dev/null
+++ b/releasenotes/notes/dreprecate_client_parameters-cb8d069e62957f7e.yaml
@@ -0,0 +1,6 @@
+---
+deprecations:
+  - |
+    Deprecate the client_parameters argument in
+    `tempest.lib.services.clients.ServiceClients`. The parameter is actually
+    not honoured already - see https://bugs.launchpad.net/tempest/+bug/1680915
diff --git a/tempest/lib/services/clients.py b/tempest/lib/services/clients.py
index eefac66..0a06c04 100644
--- a/tempest/lib/services/clients.py
+++ b/tempest/lib/services/clients.py
@@ -17,7 +17,9 @@
 import copy
 import importlib
 import inspect
+import warnings
 
+from debtcollector import removals
 from oslo_log import log as logging
 
 from tempest.lib import auth
@@ -29,7 +31,7 @@
 from tempest.lib.services import network
 from tempest.lib.services import volume
 
-
+warnings.simplefilter("once")
 LOG = logging.getLogger(__name__)
 
 
@@ -257,6 +259,7 @@
     # initialises this class using values from tempest CONF object. The wrapper
     # class should only be used by tests hosted in Tempest.
 
+    @removals.removed_kwarg('client_parameters')
     def __init__(self, credentials, identity_uri, region=None, scope='project',
                  disable_ssl_certificate_validation=True, ca_certs=None,
                  trace_requests='', client_parameters=None):
@@ -272,7 +275,12 @@
         Parameters dscv, ca_certs and trace_requests all apply to the auth
         provider as well as any service clients provided by this manager.
 
-        Any other client parameter must be set via client_parameters.
+        Any other client parameter should be set via ClientsRegistry.
+
+        Client parameter used to be set via client_parameters, but this is
+        deprecated, and it is actually already not honoured
+        anymore: https://launchpad.net/bugs/1680915.
+
         The list of available parameters is defined in the service clients
         interfaces. For reference, most clients will accept 'region',
         'service', 'endpoint_type', 'build_timeout' and 'build_interval', which
@@ -287,6 +295,10 @@
         - Volume client for 'volume' accepts 'default_volume_size'
         - Servers client from 'compute' accepts 'enable_instance_password'
 
+        If Tempest configuration is used, parameters will be loaded in the
+        Registry automatically for all service client (Tempest stable ones
+        and plugins).
+
         Examples:
 
             >>> identity_params = config.service_client_config('identity')
@@ -311,14 +323,6 @@
             for the version. Values are dictionaries of parameters that are
             going to be passed to all clients in the service client module.
 
-        Examples:
-
-            >>> params_service_x = {'param_name': 'param_value'}
-            >>> client_parameters = { 'service_x': params_service_x }
-
-            >>> params_service_y = config.service_client_config('service_y')
-            >>> client_parameters['service_y'] = params_service_y
-
         """
         self._registered_services = set([])
         self.credentials = credentials