The characteristics of anorexia nervosa and bulimia nervosa were studied in ballet dancers in full-time training and compared with other young women at school. Dancers had higher scores on the Eating Attitudes Test. Dancers were more likely to have an eating disorder when strict modified DSM-3-R criteria were applied. Currently 1 dancer (1.6%) and no student had anorexia nervosa, 1 dancer (1.6%) and 3 students (1.3%) had bulimia nervosa and 5 dancers (8.3%) and 9 students (4.2%) had an unclassified eating disorder. Another dancer had been treated for anorexia nervosa in the past. One dancer was treated for bulimia nervosa and 6 for weight loss. Dancers were more likely to have been told to increase their body weight. Dancers were not more likely to be afraid of losing control of their weight and becoming obese if they attempted weight gain, to ignore the advice to gain weight or resist gaining weight. Regular self-induced vomiting was reported by 4% of women. Dancers are at risk for the development of eating disorders. Ballet dancers are under pressure to maintain low body weight. The low body weight and menstrual disturbance found among young dancers during training are two of the characteristics of anorexia nervosa Ballet dancers use behaviours aimed at weight control and weight loss. In dancers and professional groups under intense pressure to diet, low body weight and amenorrhoea are not sufficient criteria to diagnose anorexia nervosa. These behaviours can result in binge eating and multiple behaviours aimed at preventing binge eating. Whether the characteristics of bulimia among dancers are sufficient for a diagnosis of bulimia nervosa to be made is unknown. The aim of this paper is to study the characteristics of the eating disorders anorexia nervosa, bulimia nervosa and eating disorder not otherwise specified among young ballet dancers in full-time ballet training and to provide information about the risk of development of eating disorders among young women required to maintain below average body weight while continuing above average exercise.