Fifty-nine total hip revision arthroplasties using cementless femoral components were performed in patients with focal femoral osteolytic defects before surgery. Clinical and radiographic review was performed at 2 to 5 years of follow-up evaluation. Osteolytic defects were located by Gruen zones, evaluated on postoperative radiographs, and classified as stabilized, progressive, regressing, healed, or new. There were no clinical failures in this series of patients, and no femoral revisions have been necessary. Progression of the lytic defects after revision did not occur. No new defects developed. Of the 154 preoperative osteolytic defects identified, 27 stabilized, 65 regressed, and 62 healed. One goal of revision hip surgery is to prevent osteolytic lesions from progressing, and this was achieved in 100% of patients in this series. Another goal of revision surgery is restoration of bone stock. It appears that there is a slow, steady remodeling of the lytic lesion that occurs with a well-fixed porous ingrowth prosthesis. Although this series did not show any additional benefit from cancellous allografting, the grafting technique did not use specifically designed instrumentation. Therefore, the full potential of grafting may not have been realized. If severe osteolysis is present, then regression or healing of defects can be achieved by revision to a cementless femoral component with or without the addition of cancellous allograft.