The aims of treatment of children with CDH untreated until walking age should be to reestablish the mechanics of the hip joint and avoid complications, especially avascular necosis, thus delaying the devlopment of osteoarthritis. In the child who is first seen between the ages of one and three years, considerable controversy still exists as to the merit of closed versus operative management. The average 29.3 months follow-up results in fifty congenitally dislocated hips in forty-five children with were between six and thirty-six months old when treatment was begun have been reviewed at the Department of Orthopaedic Surgery, In Je University, College of Medicine, Paik Hospital from June, 1979 to Aug, 1989. The results of this study were as follows: 1. Factors affecting method of treatment were age, degree of dislocation and acetabular index; A. Age 1) The children below ages of 18 months were treatment by closed reduction. 2) The children below ages of 18 months were treatment by open reduction with concomittant procedures. B. Degree of dislocation: Open reduction was more frequently reguired in higher degree of dislocation. C. Acetabular index: It was little influenced on method of treatment. 2. The complications were persisten subuxation (3 cases), temporary irregular ossification (16 cases) and avascular necrosis (1 cases).