During 1984, 86 women soccer players answered detailed questionnaires concerning contraceptive use, menstruation data, premenstrual and menstrual symptoms, and data concerning soccer activities including injuries. This prospective study showed that women soccer players were more susceptible to traumatic injuries during the premenstrual and menstrual period compared to the rest of the menstrual cycle (P less than 0.05), especially among players with premenstrual symptoms such as irritability/irascibility, swelling/discomfort in the breasts, and swelling/congestion in the abdomen. It was also found that women using contraceptive pills had a lower rate of traumatic injuries (P less than 0.05) compared to women who were not on the Pill. The results can be explained by the fact that oral contraceptives ameliorate some symptoms of the premenstrual and menstrual period which might also affect coordination and hence the risk of injury.