Demai used to play for the Algerian National Team in the youth stages, before he switched to play for the Tunisian National Team. He has one cap for the Algerian National Team in a 1–0 win over Qatar in 2003. He also participated in a friendly against French club Rennes two days later. Demai was recalled by the Tunisian National Team coach Humberto Coelho for the friendly game against Netherlands on 11 February 2009. He started the game, and is currently committed to the Tunisian National Team, having recorded his first official cap.