diff --git a/releasenotes/notes/config-download-in-progress-4af02517cb5a5c0c.yaml b/releasenotes/notes/config-download-in-progress-4af02517cb5a5c0c.yaml
new file mode 100644
index 000000000..ec39aaccc
--- /dev/null
+++ b/releasenotes/notes/config-download-in-progress-4af02517cb5a5c0c.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - The client (tripleoclient) now raises a new exception,
+    ConfigDownloadInProgress, if there is already an instance of the
+    tripleo.deployment.v1.config_download_deploy workflow in progress for the
+    current stack.
diff --git a/tripleoclient/exceptions.py b/tripleoclient/exceptions.py
index 2061f2730..b738b462d 100644
--- a/tripleoclient/exceptions.py
+++ b/tripleoclient/exceptions.py
@@ -57,6 +57,17 @@ class StackInProgress(Base):
     """Unable to deploy as the stack is busy"""
 
 
+class ConfigDownloadInProgress(Base):
+    """Unable to deploy as config download already in progress"""
+
+    msg_format = ("Config download already in progress with "
+                  "execution id {} for stack {}")
+
+    def __init__(self, execution_id='', stack=''):
+        message = self.msg_format.format(execution_id, stack)
+        super(ConfigDownloadInProgress, self).__init__(message)
+
+
 class RootUserExecution(Base):
     """Command was executed by a root user"""
 
diff --git a/tripleoclient/tests/workflows/test_deployment.py b/tripleoclient/tests/workflows/test_deployment.py
index 57b1c888f..80769cc1d 100644
--- a/tripleoclient/tests/workflows/test_deployment.py
+++ b/tripleoclient/tests/workflows/test_deployment.py
@@ -169,3 +169,44 @@ class TestDeploymentWorkflows(utils.TestCommand):
         ips = deployment.get_overcloud_hosts(stack, 'external')
         expected = ['4.4.4.4', '6.6.6.6', '11.11.11.11']
         self.assertEqual(sorted(expected), sorted(ips))
+
+    def test_config_download_already_in_progress(
+            self):
+        log = mock.Mock()
+        stack = mock.Mock()
+        stack.stack_name = 'stacktest'
+        clients = mock.Mock()
+        mock_execution = mock.Mock()
+        mock_execution.input = '{"plan_name": "stacktest"}'
+        mock_return = mock.Mock(return_value=[mock_execution])
+        clients.workflow_engine.executions.find = mock_return
+
+        self.assertRaises(exceptions.ConfigDownloadInProgress,
+                          deployment.config_download,
+                          log, clients, stack, 'templates', 'ssh_user',
+                          'ssh_key', 'ssh_networks', 'output_dir', False,
+                          'timeout')
+
+    @mock.patch('tripleoclient.workflows.deployment.base')
+    def test_config_download_already_in_progress_for_diff_stack(
+            self, mock_base):
+        log = mock.Mock()
+        stack = mock.Mock()
+        stack.stack_name = 'stacktest'
+        clients = mock.Mock()
+        mock_execution = mock.Mock()
+        mock_execution.input = '{"plan_name": "someotherstack"}'
+        mock_return = mock.Mock(return_value=[mock_execution])
+        clients.workflow_engine.executions.find = mock_return
+        mock_exit = mock.Mock()
+        mock_exit.__exit__ = mock.Mock()
+        mock_exit.__enter__ = mock.Mock()
+        clients.tripleoclient.messaging_websocket = mock.Mock(
+            return_value=mock_exit)
+        mock_base.wait_for_messages = mock.Mock(
+            return_value=[dict(status='SUCCESS')])
+
+        deployment.config_download(
+            log, clients, stack, 'templates', 'ssh_user',
+            'ssh_key', 'ssh_networks', 'output_dir', False,
+            'timeout')
diff --git a/tripleoclient/workflows/deployment.py b/tripleoclient/workflows/deployment.py
index 5a331780b..826831ce2 100644
--- a/tripleoclient/workflows/deployment.py
+++ b/tripleoclient/workflows/deployment.py
@@ -19,6 +19,7 @@ import socket
 import subprocess
 import tempfile
 import time
+import yaml
 
 from heatclient.common import event_utils
 from openstackclient import shell
@@ -368,10 +369,31 @@ def config_download(log, clients, stack, templates,
         workflow_input.update(
             dict(override_ansible_cfg=override_ansible_cfg_contents))
 
+    workflow_name = 'tripleo.deployment.v1.config_download_deploy'
+
+    # Check to see if any existing executions for the same stack are already in
+    # progress.
+    log.info("Checking for existing executions of config_download for "
+             "%s" % stack.stack_name)
+    for execution in workflow_client.executions.find(
+            workflow_name=workflow_name,
+            state='RUNNING'):
+
+        try:
+            exec_input = yaml.safe_load(execution.input)
+        except yaml.YAMLError as ye:
+            log.error("YAML error loading input for execution %s: %s" %
+                      (execution.id, str(ye)))
+            raise
+
+        if exec_input.get('plan_name', 'overcloud') == stack.stack_name:
+            raise exceptions.ConfigDownloadInProgress(execution.id,
+                                                      stack.stack_name)
+
     with tripleoclients.messaging_websocket() as ws:
         execution = base.start_workflow(
             workflow_client,
-            'tripleo.deployment.v1.config_download_deploy',
+            workflow_name,
             workflow_input=workflow_input
         )