In order to evaluate the onset of puberty and the presence of menstrual disorders in Finnish sportswomen with different training programs, 53 long-distance runners, 39 skiers and their 93 controls, and 63 volleyball players with 64 controls were interviewed. All the sportswomen had trained intensively for several years and were in the top category of their sport in Finland. Menarche and thelarche in all the sportswomen and also pubarche in the volleyball players developed significantly later than in their controls. The runners and skiers (43%) suffered significantly more often from menstrual irregularities than their controls (27%), whereas volleyball players (19%) did not differ from their controls (13%) in this respect. Among runners and skiers, but not among volleyball players, premenarchal start of sports activity had an aggravating effect on these endocrine disorders. Dysmenorrhea was found to occur more seldom in sportswomen than in the control subjects, and physical exercise often alleviated menstrual distress. Because the runners and skiers trained as often and used as much time for their sport as the volleyball players, the more common occurrence of their menstrual disorders may be due to the nature of training and competition activity which is characterized by endurance physical exercise.