diff --git a/src/utils/NotificationsUtils.ts b/src/utils/NotificationsUtils.ts
index 6bc0feb..5810c2c 100644
--- a/src/utils/NotificationsUtils.ts
+++ b/src/utils/NotificationsUtils.ts
@@ -80,7 +80,7 @@ export class NotificationsUtils {
 	 * @param kind The kind of notification to create
 	 */
 	public static async CreateGroupMembershipNotification(userID: number, moderatorID: number, groupID: number, kind: NotifEventType) {
-		// TODO : Delete all previous notifications
+		await this.DeleteNotificationsGroupsMembership(userID, groupID);
 
 		const n = new Notif({
 			onElemID: groupID,
@@ -104,4 +104,27 @@ export class NotificationsUtils {
 
 		await NotificationsHelper.Push(n);
 	}
+
+	/**
+	 * Delete all the notifications related to a specific group membership
+	 * 
+	 * @param userID Target user
+	 * @param groupID The ID of the target group
+	 */
+	public static async DeleteNotificationsGroupsMembership(userID: number, groupID: number) {
+		
+		const n = new Notif({
+			onElemType: NotifElemType.GROUP_MEMBERSHIP,
+			onElemID: groupID
+		});
+
+		n.destUserID = userID;
+		n.fromUserID = -1;
+		await NotificationsHelper.Delete(n);
+
+		n.destUserID = -1;
+		n.fromUserID = userID;
+		await NotificationsHelper.Delete(n);
+
+	}
 }
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