It is the author's opinion that so called epiphysiolysis is of the nature of a torsional fracture at the cervicocapital junction. The essential element in the production of the condition is the gradual and progressive anteversion of the neck of the femur. This is so characteristic that the disease should be renamed "coxa anteverta". The fundamental principle involved in the treatment of the disease lies in the prevention of the excess anteversion. This may be done by means of a brace with a pelvic-girdle attachment, in order to maintain internal rotation of the leg. In cases in which anteversion has proceeded to the point where the weight can no longer be supported and fracture with upward displacement of the shaft has occurred, reduction of the displacement under roentgenographic control and immobilization is recommended. The use of x-ray therapy for the purpose of premature ossification of the epiphyseal line is to be studied and reported upon at a later date.