diff --git a/classes/helper.php b/classes/helper.php
index 48ef85b..6d599b6 100644
--- a/classes/helper.php
+++ b/classes/helper.php
@@ -21,6 +21,7 @@
 use tool_dynamic_cohorts\cohort_manager;
 use tool_dynamic_cohorts\condition_base;
 use tool_dynamic_cohorts\rule;
+use tool_dynamic_cohorts\rule_manager;
 
 defined('MOODLE_INTERNAL') || die();
 
@@ -76,7 +77,7 @@ class helper {
     public const STUDENT_ROLE = 'student';
 
     /**
-     * Set up configuration item.
+     * Add a new configuration item.
      *
      * @param int $itemid Item ID number
      * @param string $itemtype Item type (tag, course, category).
@@ -84,7 +85,7 @@ class helper {
      * @param stdClass|null $course Course to set up enrolment method. If not set, the no enrolment method will be created.
      * @return void
      */
-    public static function set_up_item(int $itemid, string $itemtype, string $itemname, ?stdClass $course = null): void {
+    public static function add_item(int $itemid, string $itemtype, string $itemname, ?stdClass $course = null): void {
         $cohort = self::get_cohort_by_item($itemid, $itemtype);
 
         if (empty($cohort)) {
@@ -105,7 +106,7 @@ public static function set_up_item(int $itemid, string $itemtype, string $itemna
         // Create a dynamic cohort rule associated with this cohort.
         self::add_rule($cohort, $itemtype);
         // Add a tag to a custom profile field.
-        self::update_profile_field($itemtype, $itemname);
+        self::add_profile_field_item($itemtype, $itemname);
 
         // Create enrolment method for the cohort for a given course.
         if (!empty($course)) {
@@ -113,6 +114,36 @@ public static function set_up_item(int $itemid, string $itemtype, string $itemna
         }
     }
 
+    /**
+     * Remove configuration item.
+     *
+     * @param int $itemid Item ID number
+     * @param string $itemtype Item type (tag, course, category).
+     * @param string $itemname Item name.
+     * @return void
+     */
+    public static function remove_item(int $itemid, string $itemtype, string $itemname): void {
+        global $DB;
+
+        // Find cohort.
+        $cohort = self::get_cohort_by_item($itemid, $itemtype);
+        if ($cohort) {
+            // Find all courses with this cohort and delete enrolment method.
+            self::remove_enrolment_method($itemid, $itemtype);
+            // Find a rule with this cohort and delete rule and conditions.
+            $rules = $DB->get_records('tool_dynamic_cohorts', ['cohortid' => $cohort->id]);
+            foreach ($rules as $rule) {
+                $rule = rule::get_record(['id' => $rule->id]);
+                rule_manager::delete_rule($rule);
+            }
+            // Delete cohort.
+            cohort_delete_cohort($cohort);
+            // Delete tag value from custom profile field list.
+            self::delete_profile_field_item($itemtype, $itemname);
+            // Clean up user data?
+        }
+    }
+
     /**
      * Get cohort by provided item type and item id.
      *
@@ -173,11 +204,11 @@ public static function add_enrolment_method(stdClass $course, stdClass $cohort):
     /**
      * A helper  to remove enrolment method from a given course based on item details.
      *
-     * @param stdClass $course Given course.
      * @param int $itemid Item ID.
      * @param string $itemtype Item type (tag, course, category).
+     * @param int $courseid Optional course ID.
      */
-    public static function remove_enrolment_method(stdClass $course, int $itemid, string $itemtype): void {
+    public static function remove_enrolment_method(int $itemid, string $itemtype, int $courseid = 0): void {
         global $DB;
 
         $cohort = self::get_cohort_by_item($itemid, $itemtype);
@@ -189,9 +220,12 @@ public static function remove_enrolment_method(stdClass $course, int $itemid, st
                 'enrol' => 'cohort',
                 'customint1' => $cohort->id,
                 'roleid' => $studentrole->id,
-                'courseid' => $course->id,
             ];
 
+            if (!empty($courseid)) {
+                $fields['courseid'] = $courseid;
+            }
+
             $instances = $DB->get_records('enrol', $fields);
 
             if ($instances) {
@@ -213,20 +247,51 @@ public static function remove_enrolment_method(stdClass $course, int $itemid, st
      *
      * @return void
      */
-    public static function update_profile_field(string $shortname, string $newitem): void {
+    public static function add_profile_field_item(string $shortname, string $newitem): void {
         global $DB;
 
         $field = $DB->get_record('user_info_field', ['shortname' => $shortname]);
-        $fielddata = [];
-        if (!empty($field->param1)) {
-            $fielddata = explode("\n", $field->param1);
+
+        if ($field) {
+            $fielddata = [];
+            if (!empty($field->param1)) {
+                $fielddata = explode("\n", $field->param1);
+            }
+
+            if (!in_array($newitem, $fielddata)) {
+                $fielddata[] = $newitem;
+                sort($fielddata);
+                $field->param1 = implode("\n", $fielddata);
+                $DB->update_record('user_info_field', $field);
+            }
         }
+    }
 
-        if (!in_array($newitem, $fielddata)) {
-            $fielddata[] = $newitem;
-            sort($fielddata);
-            $field->param1 = implode("\n", $fielddata);
-            $DB->update_record('user_info_field', $field);
+    /**
+     * Delete a given item from profile field.
+     *
+     * @param string $shortname Field short name.
+     * @param string $itemname A new item to add to the field.
+     *
+     * @return void
+     */
+    public static function delete_profile_field_item(string $shortname, string $itemname): void {
+        global $DB;
+
+        $field = $DB->get_record('user_info_field', ['shortname' => $shortname]);
+        if ($field) {
+            $fielddata = [];
+            if (!empty($field->param1)) {
+                $fielddata = explode("\n", $field->param1);
+            }
+
+            if (in_array($itemname, $fielddata)) {
+                $key = array_search($itemname, $fielddata);
+                unset($fielddata[$key]);
+                sort($fielddata);
+                $field->param1 = implode("\n", $fielddata);
+                $DB->update_record('user_info_field', $field);
+            }
         }
     }
 
diff --git a/classes/observer.php b/classes/observer.php
index 570c9ba..46b4cbf 100644
--- a/classes/observer.php
+++ b/classes/observer.php
@@ -20,6 +20,9 @@
 use core\event\course_created;
 use core\event\tag_added;
 use core\event\tag_removed;
+use core\event\tag_deleted;
+use tool_dynamic_cohorts\rule;
+use tool_dynamic_cohorts\rule_manager;
 
 /**
  * Event observer class.
@@ -46,7 +49,7 @@ public static function tag_added(tag_added $event): void {
         $tagname = $event->other['tagrawname'];
         $course = get_course($event->other['itemid']);
 
-        helper::set_up_item($tagid, helper::ITEM_TYPE_TAG, $tagname, $course);
+        helper::add_item($tagid, helper::ITEM_TYPE_TAG, $tagname, $course);
     }
 
     /**
@@ -63,7 +66,18 @@ public static function tag_removed(tag_removed $event): void {
 
         $tagid = $event->other['tagid'];
         $course = get_course($event->other['itemid']);
-        helper::remove_enrolment_method($course, $tagid, helper::ITEM_TYPE_TAG);
+        helper::remove_enrolment_method($tagid, helper::ITEM_TYPE_TAG, $course->id);
+    }
+
+    /**
+     * Process tag_deleted event.
+     *
+     * @param tag_deleted $event The event.
+     */
+    public static function tag_deleted(tag_deleted $event): void {
+        $tagid = $event->objectid;
+        $tagname = $event->other['rawname'];
+        helper::remove_item($tagid, helper::ITEM_TYPE_TAG, $tagname);
     }
 
     /**
@@ -75,10 +89,10 @@ public static function course_created(course_created $event): void {
         global $DB;
 
         $course = get_course($event->courseid);
-        helper::set_up_item($course->id, helper::ITEM_TYPE_COURSE, $course->{helper::COURSE_NAME}, $course);
+        helper::add_item($course->id, helper::ITEM_TYPE_COURSE, $course->{helper::COURSE_NAME}, $course);
 
         $category = $DB->get_record('course_categories', ['id' => $course->category]);
-        helper::set_up_item($category->id, helper::ITEM_TYPE_CATEGORY, $category->name, $course);
+        helper::add_item($category->id, helper::ITEM_TYPE_CATEGORY, $category->name, $course);
     }
 
     /**
@@ -90,6 +104,6 @@ public static function course_category_created(course_category_created $event):
         global $DB;
 
         $category = $DB->get_record('course_categories', ['id' => $event->objectid]);
-        helper::set_up_item($category->id, helper::ITEM_TYPE_CATEGORY, $category->name);
+        helper::add_item($category->id, helper::ITEM_TYPE_CATEGORY, $category->name);
     }
 }
diff --git a/db/events.php b/db/events.php
index b1867ec..97c899d 100644
--- a/db/events.php
+++ b/db/events.php
@@ -29,6 +29,14 @@
         'eventname' => '\core\event\tag_added',
         'callback' => '\tool_enrolprofile\observer::tag_added',
     ],
+    [
+        'eventname' => '\core\event\tag_removed',
+        'callback' => '\tool_enrolprofile\observer::tag_removed',
+    ],
+    [
+        'eventname' => '\core\event\tag_deleted',
+        'callback' => '\tool_enrolprofile\observer::tag_deleted',
+    ],
     [
         'eventname' => '\core\event\course_created',
         'callback' => '\tool_enrolprofile\observer::course_created',
@@ -37,8 +45,5 @@
         'eventname' => '\core\event\course_category_created',
         'callback' => '\tool_enrolprofile\observer::course_category_created',
     ],
-    [
-        'eventname' => '\core\event\tag_removed',
-        'callback' => '\tool_enrolprofile\observer::tag_removed',
-    ],
+
 ];
diff --git a/tests/observer_test.php b/tests/observer_test.php
index 14f334b..da2a7fe 100644
--- a/tests/observer_test.php
+++ b/tests/observer_test.php
@@ -195,6 +195,50 @@ public function test_tag_removed(): void {
         $this->assertEmpty($enrol);
     }
 
+    /**
+     * Check logic when deleting a tag.
+     */
+    public function test_tag_deleted(): void {
+        global $DB;
+
+        $course = $this->getDataGenerator()->create_course();
+        $tagname = 'A tag';
+
+        core_tag_tag::set_item_tags('core', 'course', $course->id, context_course::instance($course->id), [$tagname]);
+
+        $cohort = $DB->get_record('cohort', ['name' => $tagname]);
+        $enrol = $DB->get_record('enrol', ['courseid' => $course->id, 'enrol' => 'cohort', 'customint1' => $cohort->id]);
+        $this->assertNotEmpty($enrol);
+
+        $tag = $DB->get_record('tag', ['rawname' => $tagname]);
+        $this->assertNotEmpty($tag);
+
+        $profilefielddata = $DB->get_field('user_info_field', 'param1', ['id' => $this->tagprofilefield->id]);
+        $this->assertNotEmpty($profilefielddata);
+        $this->assertTrue(in_array($tagname, explode("\n", $profilefielddata)));
+
+        $rule = $DB->get_record('tool_dynamic_cohorts', ['name' => $tagname]);
+        $this->assertNotEmpty($rule);
+        $conditions = $DB->get_records('tool_dynamic_cohorts_c', ['ruleid' => $rule->id]);
+        $this->assertCount(2, $conditions);
+
+        core_tag_tag::delete_tags([$tag->id]);
+
+        // Tag deleted.
+        $this->assertEmpty($DB->get_record('tag', ['rawname' => $tagname]));
+        // Cohort deleted.
+        $this->assertEmpty($DB->get_record('cohort', ['name' => $tagname]));
+        // Enrolment methods deleted.
+        $this->assertEmpty($DB->get_records('enrol', ['enrol' => 'cohort', 'customint1' => $cohort->id]));
+        // Rule and conditions deleted.
+        $this->assertEmpty($DB->get_record('tool_dynamic_cohorts', ['name' => $tagname]));
+        $this->assertEmpty($DB->get_record('tool_dynamic_cohorts', ['cohortid' => $cohort->id]));
+        $this->assertEmpty($DB->get_records('tool_dynamic_cohorts_c', ['ruleid' => $rule->id]));
+        // Profile field data updated.
+        $profilefielddata = $DB->get_field('user_info_field', 'param1', ['id' => $this->tagprofilefield->id]);
+        $this->assertTrue(!in_array($tagname, explode("\n", $profilefielddata)));
+    }
+
     /**
      * Check logic when creating a course.
      */