Eight patients were seen with idiopathic chondrolysis in nine hips, with from one to eight years' follow-up. The adolescent patients showed characteristic diagnostic patterns--patients in the hip and a limp. The disease occurs most frequently in black girls and in them it tends to be more severe. Threre is progressive loss of articular cartilage, frequently progressing to flexion-adduction contracture and fibrous ankylosis. The pathological process in our patients mainly consisted of chronic synovitis and loss of articular cartilate in the weight-bearing surface of the femoral head. The patients with mild cases were satisfactorily treated with physical therapy, non-weight-bearing, and analgesics. The other hips, however, did best when allowed to undergo fibrous ankylosis with the hip in a functional position.