BACKGROUND Nontraumatic avascular necrosis of the femoral head (ANFH) is a common disorder causing disability of the hip joint. The means for optimally treating this disease are still controversial. In this study we evaluated the relatively new technique of vascularized iliac bone grafting for treating ANFH. METHODS From March 1990 to March 1992, 17 hips (15 patients) with ANFH were treated using the vascularized iliac bone grafting technique in our hospital. The patients included 12 men and three women, with an average age of 38 years. Steinberg's classification was used to categorize the severity of hip disease. The clinical results were classified as excellent, good, fair and poor according to symptoms, hip function and roentgenographic changes after surgery. Life-table analysis was applied to assess graft survival and the log rank test was used to compare statistical differences between the steroid-related and nonsteroid-related groups. RESULTS Cumulatively, 16 hips (14 patients), excluding one patient (one hip) lost to follow-up, were clinically evaluated for an average of 68 months. Among 12 hips at Steinberg stage II, eight progressed to stage IV, three to stage III and only one remained at stage II. Although most hips at stage II showed mild to moderate disease progression on plain radiography, 58% of the hips (7/12) that progressed to less than IVb showed good to excellent results. In the three hips at stage III, one progressed to stage IVa and two to stage V. In the two hips at stage IV, one remained at stage IV at final follow-up and the other was lost to follow-up. The steroid-related and nonsteroid-related groups did not differ with respect to clinical results. Both groups had 63% (5/8) good to excellent results (p > 0.05, log rank test). Only four hips were converted to prosthetic arthroplasties at final follow-up. Overall, 63% (10/16) of the hips had good to excellent results, 12% had fair results and 25% had poor results. Graft survival after seven years of follow-up was 63%. CONCLUSIONS While treatment of ANFH still poses a challenge to orthopedic surgeons, the vascularized iliac bone grafting technique is a clinically acceptable option for treating the early stages of ANFH.