Hips with residual subluxation after treatment of congenital dislocation of the hip in children who were admitted in department of orthopaedic surgery, Pusan National University Hospital, from January 1980 to October 1987, are investigated with clinical data, X-ray findings, classification and treatment. Hips with residual subluxation after treatment were followed most commonly by closed reduction and cast immobilization, 15 cases, and by innominate osteotomy, 5 cases. Conservative methods as broom-skick cast or abduction brace were done for the treatment of residual subluxation in all cases, except 2 cases of femoral osteotomies. Degree of improvement was determined by periodically measuring C–E angle, acetabular index, migration percentage and the distance from tear-drop to medial metaphysis of proximal femur. The results were as follow :1. Hips with residual subluxation after treatment were found most commonly after closed reduction and cast immobilization. 2. Residual subluxation was classified as Grade Zero to Grade three by measuring the distance from tear-drop to medial metaphysis of proximal femur. There was 12% of Grade I, 48% of Grade II and 40% of Grade III. 3. The mean normalization periods from Grade I to normal, from Grade II to normal, from Grade III to normal, were 14.7 months, 26.3 months, 37.1 months, respectively. 4. Thirteen cases which more than one and half years of follow-up were possible showed improvements in acetabular index from 30.5°to 22.9°, C–E angle from 5.7°to 25.4° and migration percentage from 34.4% to 18.8%, 5. There were relatively poor results in the hips with residual subluxation after innominate osteotomy.