diff --git a/lib/classes/grades_external.php b/lib/classes/grades_external.php
index 565f268a854..f2a0e6d3739 100644
--- a/lib/classes/grades_external.php
+++ b/lib/classes/grades_external.php
@@ -38,6 +38,8 @@ class core_grades_external extends external_api {
      *
      * @return external_function_parameters
      * @since Moodle 2.7
+     * @deprecated Moodle 3.2 MDL-51373 - Please do not call this function any more.
+     * @see gradereport_user_external::get_grades_table for a similar function
      */
     public static function get_grades_parameters() {
         return new external_function_parameters(
@@ -65,6 +67,8 @@ class core_grades_external extends external_api {
      * @param  array  $userids      Array of user ids
      * @return array                Array of grades
      * @since Moodle 2.7
+     * @deprecated Moodle 3.2 MDL-51373 - Please do not call this function any more.
+     * @see gradereport_user_external::get_grades_table for a similar function
      */
     public static function get_grades($courseid, $component = null, $activityid = null, $userids = array()) {
         global $CFG, $USER, $DB;
@@ -293,6 +297,8 @@ class core_grades_external extends external_api {
      * @param  int $iteminstance    Item instance
      * @param  int $itemnumber      Item number
      * @return grade_item           A grade_item instance
+     * @deprecated Moodle 3.2 MDL-51373 - Please do not call this function any more.
+     * @see gradereport_user_external::get_grades_table for a similar function
      */
     private static function get_grade_item($courseid, $itemtype, $itemmodule = null, $iteminstance = null, $itemnumber = null) {
         $gradeiteminstance = null;
@@ -311,6 +317,8 @@ class core_grades_external extends external_api {
      *
      * @return external_description
      * @since Moodle 2.7
+     * @deprecated Moodle 3.2 MDL-51373 - Please do not call this function any more.
+     * @see gradereport_user_external::get_grades_table for a similar function
      */
     public static function get_grades_returns() {
         return new external_single_structure(
@@ -405,6 +413,15 @@ class core_grades_external extends external_api {
 
     }
 
+    /**
+     * Marking the method as deprecated.
+     *
+     * @return bool
+     */
+    public static function get_grades_is_deprecated() {
+        return true;
+    }
+
     /**
      * Returns description of method parameters
      *
diff --git a/lib/db/services.php b/lib/db/services.php
index 0cc944328e6..31486466b40 100644
--- a/lib/db/services.php
+++ b/lib/db/services.php
@@ -393,7 +393,8 @@ $functions = array(
     'core_grades_get_grades' => array(
         'classname' => 'core_grades_external',
         'methodname' => 'get_grades',
-        'description' => 'Returns student course total grade and grades for activities.
+        'description' => '** DEPRECATED ** Please do not call this function any more.
+                                     Returns student course total grade and grades for activities.
                                      This function does not return category or manual items.
                                      This function is suitable for managers or teachers not students.',
         'type' => 'read',
diff --git a/lib/upgrade.txt b/lib/upgrade.txt
index a8cccd770e4..f8398e260cd 100644
--- a/lib/upgrade.txt
+++ b/lib/upgrade.txt
@@ -13,6 +13,9 @@ information provided here is intended especially for developers.
   - get_user_max_upload_file_size()
 * The following functions have been removed and should not be used any more:
     - file_modify_html_header() - See MDL-29738 for more information.
+* core_grades_external::get_grades has been deprecated. Please do not call this function any more.
+  External function gradereport_user_external::get_grades_table can be used for retrieving the course grades table.
+  Please note that the information returned from that WS is intended for displaying (not for data consumption).
 
 === 3.1 ===