We reviewed the results for fifty-two hips in forty-two patients who had had a Pemberton pericapsular osteotomy between 1968 and 1984 as treatment for residual acetabular dysplasia of the hip. The average age of the patients at the time of the osteotomy was four years. The average duration of follow-up was ten years. At the time of the most recent follow-up, forty-two of the fifty-two hips had a rating of Severin class IA, an essentially normally developed hip. The results of the Pemberton osteotomy were unpredictable if there had been necrosis of the femoral head (without infection) preoperatively. We believe that the Pemberton osteotomy is a safe, effective procedure for the treatment of acetabular dysplasia in patients who have congenital dislocation of the hip.