diff --git a/tools/cli/app_test.go b/tools/cli/app_test.go
index da97e857044..e3b951719ce 100644
--- a/tools/cli/app_test.go
+++ b/tools/cli/app_test.go
@@ -361,6 +361,19 @@ func (s *cliAppSuite) TestRestartWorkflow_Failed() {
 	s.Equal(1, errorCode)
 }
 
+func (s *cliAppSuite) TestDiagnoseWorkflow() {
+	resp := &types.DiagnoseWorkflowExecutionResponse{Domain: "test", DiagnosticWorkflowExecution: &types.WorkflowExecution{WorkflowID: "123", RunID: uuid.New()}}
+	s.serverFrontendClient.EXPECT().DiagnoseWorkflowExecution(gomock.Any(), gomock.Any()).Return(resp, nil).Times(1)
+	err := s.app.Run([]string{"", "--do", domainName, "workflow", "diagnose", "-w", "wid", "-r", "rid"})
+	s.Nil(err)
+}
+
+func (s *cliAppSuite) TestDiagnoseWorkflow_Failed() {
+	s.serverFrontendClient.EXPECT().DiagnoseWorkflowExecution(gomock.Any(), gomock.Any()).Return(nil, &types.BadRequestError{"faked error"})
+	errorCode := s.RunErrorExitCode([]string{"", "--do", domainName, "workflow", "diagnose", "-w", "wid", "-r", "rid"})
+	s.Equal(1, errorCode)
+}
+
 func (s *cliAppSuite) TestStartWorkflow() {
 	resp := &types.StartWorkflowExecutionResponse{RunID: uuid.New()}
 	s.serverFrontendClient.EXPECT().StartWorkflowExecution(gomock.Any(), gomock.Any()).Return(resp, nil).Times(2)
diff --git a/tools/cli/workflow.go b/tools/cli/workflow.go
index f464fc4b580..8291c4dcf0b 100644
--- a/tools/cli/workflow.go
+++ b/tools/cli/workflow.go
@@ -38,6 +38,13 @@ func newWorkflowCommands() []cli.Command {
 			Flags:   flagsForExecution,
 			Action:  RestartWorkflow,
 		},
+		{
+			Name:    "diagnose",
+			Aliases: []string{"diag"},
+			Usage:   "diagnoses a previous workflow execution",
+			Flags:   flagsForExecution,
+			Action:  DiagnoseWorkflow,
+		},
 		{
 			Name:        "activity",
 			Aliases:     []string{"act"},
diff --git a/tools/cli/workflow_commands.go b/tools/cli/workflow_commands.go
index 65e9d5cc5a6..ae8e6ca5149 100644
--- a/tools/cli/workflow_commands.go
+++ b/tools/cli/workflow_commands.go
@@ -76,6 +76,37 @@ func RestartWorkflow(c *cli.Context) {
 	}
 }
 
+// DiagnoseWorkflow diagnoses a workflow execution
+func DiagnoseWorkflow(c *cli.Context) {
+	wfClient := getWorkflowClient(c)
+
+	domain := getRequiredGlobalOption(c, FlagDomain)
+	wid := getRequiredOption(c, FlagWorkflowID)
+	rid := getRequiredOption(c, FlagRunID)
+
+	ctx, cancel := newContext(c)
+	defer cancel()
+	resp, err := wfClient.DiagnoseWorkflowExecution(
+		ctx,
+		&types.DiagnoseWorkflowExecutionRequest{
+			Domain: domain,
+			WorkflowExecution: &types.WorkflowExecution{
+				WorkflowID: wid,
+				RunID:      rid,
+			},
+			Identity: getCliIdentity(),
+		},
+	)
+
+	if err != nil {
+		ErrorAndExit("Diagnose workflow failed.", err)
+	} else {
+		fmt.Println("Workflow diagnosis started. Query the diagnostic workflow to get diagnostics report.")
+		fmt.Println("============Diagnostic Workflow details============")
+		fmt.Printf("Domain: %s, Workflow Id: %s, Run Id: %s\n", resp.GetDomain(), resp.GetDiagnosticWorkflowExecution().GetWorkflowID(), resp.GetDiagnosticWorkflowExecution().GetRunID())
+	}
+}
+
 // ShowHistory shows the history of given workflow execution based on workflowID and runID.
 func ShowHistory(c *cli.Context) {
 	wid := getRequiredOption(c, FlagWorkflowID)