Idiopathic chondrolysis of the hip is characterized by the destruction of the articular cartilage due to an unknown cause, principally affecting women during adolescence and producing premature degeneration of the hip. Twelve cases (11 patients) were reviewed at our hospital, with an average follow-up period of 13.2 years, during which a clinical and radiologic study was performed. Despite the treatment implemented, idiopathic chondrolysis of the hip causes progressive degeneration of the joint with the appearance of almost constant pain, stiffness, and anomalous positions. Radiologic studies show concentric narrowing of the articular space, decrease in the width of the femoral head and neck, and shortening of the affected member due to alteration in the growth physis of the upper extremity of the femur.