diff --git a/src/controllers/GroupsController.ts b/src/controllers/GroupsController.ts
index 1b7e545..7d92280 100644
--- a/src/controllers/GroupsController.ts
+++ b/src/controllers/GroupsController.ts
@@ -8,6 +8,8 @@ import { GroupSettings } from "../entities/GroupSettings";
 import { removeHTMLNodes, checkURL } from "../utils/StringUtils";
 import { findKey } from "../utils/ArrayUtils";
 import { checkVirtualDirectoryAvailability, VirtualDirType } from "../utils/VirtualDirsUtils";
+import { NotificationsUtils } from "../utils/NotificationsUtils";
+import { NotifEventType } from "../entities/Notification";
 
 /**
  * Groups API controller
@@ -303,7 +305,9 @@ export class GroupsController {
 		
 		await GroupsHelper.SendInvitation(groupID, userID);
 
-		// TODO : Create a notification
+		// Create a notification
+		await NotificationsUtils.CreateGroupMembershipNotification(
+			userID, h.getUserId(), groupID, NotifEventType.SENT_GROUP_MEMBERSHIP_INVITATION)
 
 		h.success("The user has been successfully invited to join the group!");
 	}
diff --git a/src/entities/Notification.ts b/src/entities/Notification.ts
index 5e32d71..89f11f9 100644
--- a/src/entities/Notification.ts
+++ b/src/entities/Notification.ts
@@ -51,7 +51,7 @@ export interface NotifBuilder {
 	id ?: number,
 	timeCreate ?: number,
 	seen ?: boolean,
-	fromUserID: number,
+	fromUserID ?: number,
 	destUserID ?: number,
 	onElemID ?: number,
 	onElemType: NotifElemType,
@@ -65,7 +65,7 @@ export class Notif implements NotifBuilder {
 	id ?: number;
 	timeCreate ?: number;
 	seen ?: boolean;
-	fromUserID: number;
+	fromUserID ?: number;
 	destUserID ?: number;
 	onElemID ?: number;
 	onElemType: NotifElemType;
diff --git a/src/helpers/NotificationsHelper.ts b/src/helpers/NotificationsHelper.ts
index 97bca7a..de7313d 100644
--- a/src/helpers/NotificationsHelper.ts
+++ b/src/helpers/NotificationsHelper.ts
@@ -113,7 +113,30 @@ export class NotificationsHelper {
 		}
 
 
-		// TODO : continue
+		// Groups membership notifications
+		else if (n.onElemType == NotifElemType.GROUP_MEMBERSHIP) {
+
+			// Complete the notification
+			n.fromContainerType = NotifElemType.EMPTY;
+			n.fromContainerID = 0;
+
+			// Check whether the notification has to be pushed to a single user
+			// or to all the moderators of the group
+			if(n.hasDestUserID) {
+
+				//Push the notification in private way (if it has a destination,
+				//generally the target user of the membership request)
+				await this.PushPrivate(n);
+
+			}
+
+			else {
+
+				// Push the notification to all the moderators of the group
+				throw new Error("//TODO Push notification to all members of the group");
+
+			}
+		}
 
 		// Unsupported notification type
 		else {
diff --git a/src/utils/NotificationsUtils.ts b/src/utils/NotificationsUtils.ts
index 9a4fad6..6bc0feb 100644
--- a/src/utils/NotificationsUtils.ts
+++ b/src/utils/NotificationsUtils.ts
@@ -70,4 +70,38 @@ export class NotificationsUtils {
 			fromUserID: userOne,
 		}));
 	}
+
+	/**
+	 * Create & push a group membership notification
+	 * 
+	 * @param userID The ID of the target user for the membership
+	 * @param moderatorID The ID of the moderator creating the notification (0 if it is the user)
+	 * @param groupID The ID of the target group
+	 * @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
+
+		const n = new Notif({
+			onElemID: groupID,
+			onElemType: NotifElemType.GROUP_MEMBERSHIP,
+			type: kind
+		});
+
+
+		// The notification must be sent to all the moderators of the group
+		if(moderatorID < 1) {
+			n.fromUserID = userID;
+			n.destUserID = -1;
+		}
+
+		// We specify both the source and the destination of the notification
+		// not to broadcast the notification to all the group members
+		else {
+			n.fromUserID = moderatorID;
+			n.destUserID = userID;
+		}
+
+		await NotificationsHelper.Push(n);
+	}
 }
\ No newline at end of file