A retrospective study of 59 congenitally dislocated hips was undertaken to assess the relationship between the quality of a closed reduction and the eventual outcome. Good closed reductions were associated with rapid improvement of the acetabular angle and the center edge (CE) angle and a low incidence of avascular necrosis (AVN). Adequate reductions with up to 7 mm of widening of the joint on arthrogram had a good final outcome in 11 of 13 hips with a slower rate of improvement of the acetabular and CE angles and a low rate of AVN. Hips with poor or indeterminate reductions had an acceptable outcome in only five of 23 hips, did not benefit from prolonged closed treatment, and had a 57% incidence of AVN. Patients with marked ligamentous laxity often fared poorly, required prolonged treatment, and had a high incidence of AVN.