diff --git a/mod/quiz/classes/grade_calculator.php b/mod/quiz/classes/grade_calculator.php
index 60f87febd9e..f0d74f7735a 100644
--- a/mod/quiz/classes/grade_calculator.php
+++ b/mod/quiz/classes/grade_calculator.php
@@ -91,6 +91,11 @@ class grade_calculator {
             // we will get a divide by zero error.
             self::update_quiz_maximum_grade(0);
         }
+
+        $callbackclasses = \core_component::get_plugin_list_with_class('quiz', 'quiz_structure_modified');
+        foreach ($callbackclasses as $callbackclass) {
+            component_class_callback($callbackclass, 'callback', [$quiz->id]);
+        }
     }
 
     /**
diff --git a/mod/quiz/report/statistics/classes/quiz_structure_modified.php b/mod/quiz/report/statistics/classes/quiz_structure_modified.php
new file mode 100644
index 00000000000..1cd8b52e8c9
--- /dev/null
+++ b/mod/quiz/report/statistics/classes/quiz_structure_modified.php
@@ -0,0 +1,53 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace quiz_statistics;
+
+use core\dml\sql_join;
+
+/**
+ * Clear the statistics cache when the quiz structure is modified.
+ *
+ * @package   quiz_statistics
+ * @copyright 2023 onwards Catalyst IT EU {@link https://catalyst-eu.net}
+ * @author    Mark Johnson <mark.johnson@catalyst-eu.net>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class quiz_structure_modified {
+    /**
+     * Clear the statistics cache.
+     *
+     * @param int $quizid The quiz to clear the cache for.
+     * @return void
+     */
+    public static function callback(int $quizid): void {
+        global $DB, $CFG;
+        require_once($CFG->dirroot . '/mod/quiz/report/statistics/statisticslib.php');
+        require_once($CFG->dirroot . '/mod/quiz/report/statistics/report.php');
+        $quiz = $DB->get_record('quiz', ['id' => $quizid]);
+        if (!$quiz) {
+            throw new \coding_exception('Could not find quiz with ID ' . $quizid . '.');
+        }
+        $qubaids = quiz_statistics_qubaids_condition(
+            $quiz->id,
+            new sql_join(),
+            $quiz->grademethod
+        );
+
+        $report = new \quiz_statistics_report();
+        $report->clear_cached_data($qubaids);
+    }
+}
diff --git a/mod/quiz/report/statistics/tests/quiz_structure_modified_test.php b/mod/quiz/report/statistics/tests/quiz_structure_modified_test.php
new file mode 100644
index 00000000000..055a28a742f
--- /dev/null
+++ b/mod/quiz/report/statistics/tests/quiz_structure_modified_test.php
@@ -0,0 +1,88 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+namespace quiz_statistics;
+
+defined('MOODLE_INTERNAL') || die();
+
+global $CFG;
+require_once($CFG->dirroot . '/mod/quiz/tests/quiz_question_helper_test_trait.php');
+
+use core\progress\none;
+use mod_quiz\grade_calculator;
+use mod_quiz\quiz_settings;
+
+/**
+ * Unit tests for quiz_statistics\event\observer\slots_updated
+ *
+ * @package   quiz_statistics
+ * @copyright 2023 onwards Catalyst IT EU {@link https://catalyst-eu.net}
+ * @author    Mark Johnson <mark.johnson@catalyst-eu.net>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @covers    \quiz_statistics\quiz_structure_modified
+ */
+class quiz_structure_modified_test extends \advanced_testcase {
+    use \quiz_question_helper_test_trait;
+
+    /**
+     * Clear the statistics cache for a quiz when it structure is modified.
+     *
+     * When recompute_quiz_sumgrades() is called, it should trigger this plugin's quiz_structure_modified callback
+     * which clears the statistics cache for the quiz.
+     *
+     * @return void
+     */
+    public function test_clear_cache_on_structure_modified(): void {
+        global $DB;
+        $this->resetAfterTest(true);
+
+        // Create and attempt a quiz.
+        $generator = $this->getDataGenerator();
+        $user = $generator->create_user();
+        $course = $generator->create_course();
+        $quiz = $this->create_test_quiz($course);
+        $questiongenerator = $generator->get_plugin_generator('core_question');
+        $category = $questiongenerator->create_question_category();
+        $question = $questiongenerator->create_question('match', null, ['category' => $category->id]);
+        $questiongenerator->update_question($question);
+        quiz_add_quiz_question($question->id, $quiz);
+        [, , $attempt] = $this->attempt_quiz($quiz, $user);
+
+        // Run the statistics calculation to prime the cache.
+        $report = new \quiz_statistics_report();
+        $questions = $report->load_and_initialise_questions_for_calculations($quiz);
+        $report->get_all_stats_and_analysis(
+            $quiz,
+            $quiz->grademethod,
+            \question_attempt::ALL_TRIES,
+            new \core\dml\sql_join(),
+            $questions,
+            new none(),
+        );
+
+        $hashcode = quiz_statistics_qubaids_condition($quiz->id, new \core\dml\sql_join(), $quiz->grademethod)->get_hash_code();
+
+        $this->assertTrue($DB->record_exists('quiz_statistics', ['hashcode' => $hashcode]));
+        $this->assertTrue($DB->record_exists('question_statistics', ['hashcode' => $hashcode]));
+        $this->assertTrue($DB->record_exists('question_response_analysis', ['hashcode' => $hashcode]));
+
+        // Recompute sumgrades, which triggers the quiz_structure_modified callback.
+        grade_calculator::create($attempt->get_quizobj())->recompute_quiz_sumgrades();
+
+        $this->assertFalse($DB->record_exists('quiz_statistics', ['hashcode' => $hashcode]));
+        $this->assertFalse($DB->record_exists('question_statistics', ['hashcode' => $hashcode]));
+        $this->assertFalse($DB->record_exists('question_response_analysis', ['hashcode' => $hashcode]));
+    }
+}
diff --git a/mod/quiz/upgrade.txt b/mod/quiz/upgrade.txt
index 8fd9bf70ac3..ba58d8552ec 100644
--- a/mod/quiz/upgrade.txt
+++ b/mod/quiz/upgrade.txt
@@ -1,5 +1,10 @@
 This files describes API changes in the quiz code.
 
+=== 4.4 ===
+* A quiz_structure_modified callback has been added for quiz_ plugins, called from
+  grade_calculator::recompute_quiz_sumgrades(). Plugins can implement this by creating a `quiz_structure_modified`
+  class in their namespace with a static `callback` method, see quiz_statistics as an example.
+
 === 4.3 ===
 
 * The method get_questions() has a new parameter 'requirequestionfullyloaded' which can be used to instruct whether the