diff --git a/rcl/include/rcl/graph.h b/rcl/include/rcl/graph.h
index 84b855c14..5053d5d3a 100644
--- a/rcl/include/rcl/graph.h
+++ b/rcl/include/rcl/graph.h
@@ -75,6 +75,8 @@ typedef rmw_names_and_types_t rcl_names_and_types_t;
  * \return `RCL_RET_OK` if the query was successful, or
  * \return `RCL_RET_NODE_INVALID` if the node is invalid, or
  * \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAME` if the node name is invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAMESPACE` if the node namespace is invalid, or
  * \return `RCL_RET_ERROR` if an unspecified error occurs.
  */
 RCL_PUBLIC
@@ -122,6 +124,8 @@ rcl_get_publisher_names_and_types_by_node(
  * \return `RCL_RET_OK` if the query was successful, or
  * \return `RCL_RET_NODE_INVALID` if the node is invalid, or
  * \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAME` if the node name is invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAMESPACE` if the node namespace is invalid, or
  * \return `RCL_RET_ERROR` if an unspecified error occurs.
  */
 RCL_PUBLIC
@@ -168,6 +172,8 @@ rcl_get_subscriber_names_and_types_by_node(
  * \return `RCL_RET_OK` if the query was successful, or
  * \return `RCL_RET_NODE_INVALID` if the node is invalid, or
  * \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAME` if the node name is invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAMESPACE` if the node namespace is invalid, or
  * \return `RCL_RET_ERROR` if an unspecified error occurs.
  */
 RCL_PUBLIC
@@ -213,6 +219,8 @@ rcl_get_service_names_and_types_by_node(
  * \return `RCL_RET_OK` if the query was successful, or
  * \return `RCL_RET_NODE_INVALID` if the node is invalid, or
  * \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAME` if the node name is invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAMESPACE` if the node namespace is invalid, or
  * \return `RCL_RET_ERROR` if an unspecified error occurs.
  */
 RCL_PUBLIC
@@ -257,6 +265,8 @@ rcl_get_client_names_and_types_by_node(
  * \return `RCL_RET_OK` if the query was successful, or
  * \return `RCL_RET_NODE_INVALID` if the node is invalid, or
  * \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAME` if the node name is invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAMESPACE` if the node namespace is invalid, or
  * \return `RCL_RET_ERROR` if an unspecified error occurs.
  */
 RCL_PUBLIC
diff --git a/rcl/src/rcl/graph.c b/rcl/src/rcl/graph.c
index c43722775..331d78027 100644
--- a/rcl/src/rcl/graph.c
+++ b/rcl/src/rcl/graph.c
@@ -22,14 +22,50 @@ extern "C"
 #include "rcl/error_handling.h"
 #include "rcutils/allocator.h"
 #include "rcutils/types.h"
+#include "rmw/error_handling.h"
 #include "rmw/get_node_info_and_types.h"
 #include "rmw/get_service_names_and_types.h"
 #include "rmw/get_topic_names_and_types.h"
 #include "rmw/names_and_types.h"
 #include "rmw/rmw.h"
+#include "rmw/validate_namespace.h"
+#include "rmw/validate_node_name.h"
 
 #include "./common.h"
 
+rcl_ret_t
+__validate_node_name_and_namespace(
+  const char * node_name,
+  const char * node_namespace)
+{
+  int validation_result = 0;
+  rmw_ret_t rmw_ret = rmw_validate_namespace(node_namespace, &validation_result, NULL);
+
+  if (RMW_RET_OK != rmw_ret) {
+    RCL_SET_ERROR_MSG(rmw_get_error_string().str);
+    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
+  }
+  if (validation_result != RMW_NAMESPACE_VALID) {
+    const char * msg = rmw_namespace_validation_result_string(validation_result);
+    RCL_SET_ERROR_MSG_WITH_FORMAT_STRING("%s, result: %d", msg, validation_result);
+    return RCL_RET_NODE_INVALID_NAMESPACE;
+  }
+
+  validation_result = 0;
+  rmw_ret = rmw_validate_node_name(node_name, &validation_result, NULL);
+  if (RMW_RET_OK != rmw_ret) {
+    RCL_SET_ERROR_MSG(rmw_get_error_string().str);
+    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
+  }
+  if (RMW_NODE_NAME_VALID != validation_result) {
+    const char * msg = rmw_node_name_validation_result_string(validation_result);
+    RCL_SET_ERROR_MSG_WITH_FORMAT_STRING("%s, result: %d", msg, validation_result);
+    return RCL_RET_NODE_INVALID_NAME;
+  }
+
+  return RCL_RET_OK;
+}
+
 rcl_ret_t
 rcl_get_publisher_names_and_types_by_node(
   const rcl_node_t * node,
@@ -51,11 +87,14 @@ rcl_get_publisher_names_and_types_by_node(
   if (strlen(node_namespace) > 0) {
     valid_namespace = node_namespace;
   }
-  rmw_ret_t rmw_ret;
-  rmw_ret = rmw_names_and_types_check_zero(topic_names_and_types);
-  if (rmw_ret != RMW_RET_OK) {
+  rmw_ret_t rmw_ret = rmw_names_and_types_check_zero(topic_names_and_types);
+  if (RMW_RET_OK != rmw_ret) {
     return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
   }
+  rcl_ret_t rcl_ret = __validate_node_name_and_namespace(node_name, valid_namespace);
+  if (RCL_RET_OK != rcl_ret) {
+    return rcl_ret;
+  }
   rcutils_allocator_t rcutils_allocator = *allocator;
   rmw_ret = rmw_get_publisher_names_and_types_by_node(
     rcl_node_get_rmw_handle(node),
@@ -95,6 +134,10 @@ rcl_get_subscriber_names_and_types_by_node(
     return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
   }
   rcutils_allocator_t rcutils_allocator = *allocator;
+  rcl_ret_t rcl_ret = __validate_node_name_and_namespace(node_name, valid_namespace);
+  if (RCL_RET_OK != rcl_ret) {
+    return rcl_ret;
+  }
   rmw_ret = rmw_get_subscriber_names_and_types_by_node(
     rcl_node_get_rmw_handle(node),
     &rcutils_allocator,
@@ -131,6 +174,10 @@ rcl_get_service_names_and_types_by_node(
   if (rmw_ret != RMW_RET_OK) {
     return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
   }
+  rcl_ret_t rcl_ret = __validate_node_name_and_namespace(node_name, valid_namespace);
+  if (RCL_RET_OK != rcl_ret) {
+    return rcl_ret;
+  }
   rcutils_allocator_t rcutils_allocator = *allocator;
   rmw_ret = rmw_get_service_names_and_types_by_node(
     rcl_node_get_rmw_handle(node),
@@ -167,6 +214,10 @@ rcl_get_client_names_and_types_by_node(
   if (rmw_ret != RMW_RET_OK) {
     return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
   }
+  rcl_ret_t rcl_ret = __validate_node_name_and_namespace(node_name, valid_namespace);
+  if (RCL_RET_OK != rcl_ret) {
+    return rcl_ret;
+  }
   rcutils_allocator_t rcutils_allocator = *allocator;
   rmw_ret = rmw_get_client_names_and_types_by_node(
     rcl_node_get_rmw_handle(node),
diff --git a/rcl/test/rcl/test_graph.cpp b/rcl/test/rcl/test_graph.cpp
index bc40cba49..f24ec6e7c 100644
--- a/rcl/test/rcl/test_graph.cpp
+++ b/rcl/test/rcl/test_graph.cpp
@@ -274,7 +274,7 @@ TEST_F(
   rcl_allocator_t zero_allocator = static_cast<rcl_allocator_t>(
     rcutils_get_zero_initialized_allocator());
   rcl_node_t zero_node = rcl_get_zero_initialized_node();
-  const char * unknown_node_name = "/test_rcl_get_publisher_names_and_types_by_node";
+  const char * unknown_node_name = "test_rcl_get_publisher_names_and_types_by_node";
   const char * unknown_node_ns = "/test/namespace";
   rcl_names_and_types_t nat = rcl_get_zero_initialized_names_and_types();
   // invalid node
@@ -311,15 +311,15 @@ TEST_F(
   // test valid strings with invalid node names
   ret = rcl_get_publisher_names_and_types_by_node(
     this->node_ptr, &allocator, false, "", "", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAME, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   ret = rcl_get_publisher_names_and_types_by_node(
-    this->node_ptr, &allocator, false, "_InvalidNodeName", "", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+    this->node_ptr, &allocator, false, "_!InvalidNodeName", "", &nat);
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAME, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   ret = rcl_get_publisher_names_and_types_by_node(
     this->node_ptr, &allocator, false, this->test_graph_node_name, "_!invalidNs", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAMESPACE, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   // invalid names and types
   ret = rcl_get_publisher_names_and_types_by_node(
@@ -359,7 +359,7 @@ TEST_F(
   rcl_allocator_t zero_allocator = static_cast<rcl_allocator_t>(
     rcutils_get_zero_initialized_allocator());
   rcl_node_t zero_node = rcl_get_zero_initialized_node();
-  const char * unknown_node_name = "/test_rcl_get_subscriber_names_and_types_by_node";
+  const char * unknown_node_name = "test_rcl_get_subscriber_names_and_types_by_node";
   const char * unknown_node_ns = "/test/namespace";
   rcl_names_and_types_t nat = rcl_get_zero_initialized_names_and_types();
   // invalid node
@@ -396,15 +396,15 @@ TEST_F(
   // test valid strings with invalid node names
   ret = rcl_get_subscriber_names_and_types_by_node(
     this->node_ptr, &allocator, false, "", "", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAME, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   ret = rcl_get_subscriber_names_and_types_by_node(
-    this->node_ptr, &allocator, false, "_InvalidNodeName", "", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+    this->node_ptr, &allocator, false, "_!InvalidNodeName", "", &nat);
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAME, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   ret = rcl_get_subscriber_names_and_types_by_node(
     this->node_ptr, &allocator, false, this->test_graph_node_name, "_!invalidNs", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAMESPACE, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   // invalid names and types
   ret = rcl_get_subscriber_names_and_types_by_node(
@@ -441,7 +441,7 @@ TEST_F(
   rcl_allocator_t zero_allocator = static_cast<rcl_allocator_t>(
     rcutils_get_zero_initialized_allocator());
   rcl_node_t zero_node = rcl_get_zero_initialized_node();
-  const char * unknown_node_name = "/test_rcl_get_service_names_and_types_by_node";
+  const char * unknown_node_name = "test_rcl_get_service_names_and_types_by_node";
   const char * unknown_node_ns = "/test/namespace";
   rcl_names_and_types_t nat = rcl_get_zero_initialized_names_and_types();
   // invalid node
@@ -478,15 +478,15 @@ TEST_F(
   // test valid strings with invalid node names
   ret = rcl_get_service_names_and_types_by_node(
     this->node_ptr, &allocator, "", "", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAME, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   ret = rcl_get_service_names_and_types_by_node(
-    this->node_ptr, &allocator, "_InvalidNodeName", "", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+    this->node_ptr, &allocator, "_!InvalidNodeName", "", &nat);
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAME, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   ret = rcl_get_service_names_and_types_by_node(
     this->node_ptr, &allocator, this->test_graph_node_name, "_!invalidNs", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAMESPACE, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   // invalid names and types
   ret = rcl_get_service_names_and_types_by_node(
@@ -523,7 +523,8 @@ TEST_F(
   rcl_allocator_t zero_allocator = static_cast<rcl_allocator_t>(
     rcutils_get_zero_initialized_allocator());
   rcl_node_t zero_node = rcl_get_zero_initialized_node();
-  const char * unknown_node_name = "/test_rcl_get_client_names_and_types_by_node";
+  const char * unknown_node_name = "test_rcl_get_client_names_and_types_by_node";
+  const char * unknown_node_ns = "/test/namespace";
   rcl_names_and_types_t nat = rcl_get_zero_initialized_names_and_types();
   // invalid node
   ret = rcl_get_client_names_and_types_by_node(
@@ -559,11 +560,15 @@ TEST_F(
   // test valid strings with invalid node names
   ret = rcl_get_client_names_and_types_by_node(
     this->node_ptr, &allocator, "", "", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAME, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   ret = rcl_get_client_names_and_types_by_node(
-    this->node_ptr, &allocator, "_InvalidNodeName", "", &nat);
-  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+    this->node_ptr, &allocator, "_!InvalidNodeName", "", &nat);
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAME, ret) << rcl_get_error_string().str;
+  rcl_reset_error();
+  ret = rcl_get_client_names_and_types_by_node(
+    this->node_ptr, &allocator, this->test_graph_node_name, "_!invalidNs", &nat);
+  EXPECT_EQ(RCL_RET_NODE_INVALID_NAMESPACE, ret) << rcl_get_error_string().str;
   rcl_reset_error();
   // invalid names and types
   ret = rcl_get_client_names_and_types_by_node(
@@ -575,6 +580,11 @@ TEST_F(
     this->node_ptr, &allocator, unknown_node_name, "", &nat);
   EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
   rcl_reset_error();
+  // unknown node namespace
+  ret = rcl_get_client_names_and_types_by_node(
+    this->node_ptr, &allocator, this->test_graph_node_name, unknown_node_ns, &nat);
+  EXPECT_EQ(RCL_RET_ERROR, ret) << rcl_get_error_string().str;
+  rcl_reset_error();
   // valid call
   ret = rcl_get_client_names_and_types_by_node(
     this->node_ptr, &allocator, this->test_graph_node_name, "", &nat);