Ajunwa performed as a track and field athlete and specialised in the 100m, 200m and long jump. She competed at the 1990 Commonwealth Games, winning a bronze medal in the 4 x 100 metres relay, and competed at the African Championships in 1989 and the All Africa Games in 1991 where she won gold medals in the long jump. Ajunwa was banned from the sport for four years after failing a drug test in 1992 despite maintaining her innocence.