Mustapha competed in four Paralympics, winning eight medals six of which were gold. His first experience in the Paralympics was in 1984 when he competed in the 100m, 400m and shot putt and won a gold medal in the A1-3 800m. The 1988 Summer Paralympics would prove to be his best games winning gold in the 200m, 1500m, 5000m and Marathon and winning the silver in the 100m just 0.12 seconds behind Canada's Daniel Westley. After a performance like that it was going to be difficult to match it in the 1992 but the 1992 were a complete disaster as Mustapha missed out on the medals in all his events 100m, 200m,800m and marathon. He did get back to medal winning ways in his final games in 1996 winning a gold in the 4 × 400 m and a bronze in the 800m as well as competing in the 100m, 400m and marathon.