In the 1992 Olympic Games in Barcelona Marie-Jose won the 400m title becoming the first Frenchwoman to win an athletics Olympic gold medal since 1968 when Colette Besson won the same event in Mexico City.

Four years later at the Olympics in Atlanta she astonished the world by achieving a rare 200/400 m double gold medal, meanwhile setting the Olympic record time of 48.25 seconds. Perec was the first athlete to win the 400 m title twice and to accomplish the 200/400 gold medal double at a non-boycotted Olympics.