Five patients with chronic and subacute unreduced fracture-dislocation of the hip were treated successfully by total hip arthroplasty. The regimen developed was as follows: The first stage, in general, consisted of removal of the head of the femur and reduction and internal fixation of the acetabular fragments. Surgery to the sciatic nerve, if necessary, was done at this time. This was followed by total hip arthroplasty in five to eight weeks as a second stage. If severe fracture of the acetabulum occurred with dislocation of the hip, and the hip could be reduced, total hip arthroplasty could be done in one stage, either soon after the injury or at a later time. Such a procedure restores almost normal function to a hip that otherwise may remain painful and stiff because of traumatic arthritis and disturbed anatomical relationships of the acetabulum to the femoral head, and may save the patient much time and suffering.