The professional ballet dancer presents all of the problems of any vigorous athlete. The problems include osteochondral fractures, fatigue fractures, sprains, chronic ligamentous instability of the knee, meniscal tears, impingement syndrome, degenerative arthritis of multiple joints and low back pain. Attention to minor problems with sound conservative therapy can avoid many major developments and lost hours. Observations included the extraordinary external rotation of at the hip without demonstrable alteration in the hip version angle and hypertrophy of the femur, tibia and particularly the second metatarsal (in female dancers). Careful evaluation of the range of motion of the extremities, serial roentgenographic examination, and systematic review of previous injuries, training programs and rehearsal techniques have been evaluated in a series of cases to provide the basis for advice to directors and teachers of the ballet.