We surveyed 54 female dancers in two professional ballet companies. A total of 27 fractures were reported in 17 dancers. Metatarsal fractures were the most common (63%), followed by fractures of the tibia (22%) and spine (7%). Dancers who danced greater than 5 hours per day were significantly more likely to have a stress fracture than those dancing less than 5 hours per day. Dancers in the stress fracture group also had a significantly longer duration of amenorrhea than those in the group with no stress fractures. No significant difference was found between the dancers who had stress fractures and those who did not with regard to any of the other variables examined. These data suggest that prolonged amenorrheic intervals and heavy training schedules may predispose ballet dancers to stress fractures. Of the 17 dancers with stress fractures, only 1 had neither of these risk factors.