This study examined risk factors and triggers for eating disorders in female athletes. Subjects included were all of the elite female athletes in Norway (N = 603), ages 12-35 yr, representing six groups of sports: technical, endurance, aesthetic, weight dependent, ball games, and power sports. The Eating Disorder Inventory was used to classify individuals at risk for eating disorders. Of the 117 athletes defined at risk, 103 were administered a structured clinical interview for eating disorders. A comparison group was also interviewed, consisting of 30 athletes chosen at random from a pool not at risk and matched to the at-risk subjects on age, community of residence, and sport. Ninety-two of the at-risk athletes met criteria for anorexia nervosa, bulimia nervosa, or anorexia athletica. The prevalence of eating disorders was higher in sports emphasizing leanness or a specific weight than in sports where these are less important. Compared with controls, eating disordered athletes began both sports-specific training and dieting earlier, and felt that puberty occurred too early for optimal performance. Trigger factors associated with the onset of eating disorders were prolonged periods of dieting, frequent weight fluctuations, a sudden increase in training volume, and traumatic events such as injury or loss of a coach.