1) Twenty-nine children aged 18 months to 7 years with 40 congenitally dislocated hips, were treated between 1964 and 1971. Six hips had a closed reduction, 34 had an open reduction and capsulorrhaphy, and all had an innominate osteotomy. 2) Complications of the treatment included 2 joint infections. Of 11 hips which were unstable post-operatively, more than half were due to errors of the operative technique, and 8 required further surgery. Avascular necrosis of the femoral head occured in 3 hips post-operatively, and another 3 showed irregular ossification of the femoral epiphysis. All 6 hips had had an open reduction, and were mainly in older children who had inadequate pre-operative traction. 18 hips were stiff post-operatively ; 17 had had an open reduction ; Seven of eleven were improved by traction and physiotherapy. 3) The average length of follow-up was 4 years. Although only 70 p. 100 of the hips were clinically satisfactory, 92 p. 100 had excellent or good anatomical results as seen on radiographs.