BACKGROUND A vascularized pedicle iliac bone graft combined with transtrochanteric anterior rotational osteotomy was performed in patients with extensive necrosis in whom the necrotic area occupied more than two-thirds of the weight-bearing zone of the femoral head. The purpose of this procedure is to supply vascularity and mechanical strength to the avascular femoral head. METHODS Seventeen hips in 14 patients (8 male, 6 female) whose average age at surgery was 37.9 (range 21-51) years underwent this procedure between June 1992 and December 2002. These hips (stage 2 in 3 hips, stage 3A in 13 hips, and stage 3B in 1 hip) were examined for changes according to the Japanese Orthopedic Association (JOA ) score and the presence or absence of progression of the clinical stage at least 1 year after surgery. RESULTS The mean JOA score improved from 67.8 points preoperatively to 78.1 points by 18-133 (mean 50.7) months postoperatively. There was no disease progression to a more advanced stage in 12 of 17 hips (71%) postoperatively. CONCLUSIONS A vascularized pedicle iliac bone graft combined with transtrochanteric anterior rotational osteotomy to treat avascular necrosis of the femoral head is considered promising for joint preservation.