The authors reviewed the clinical and radiographic results of 31 bipolar hip arthroplasties performed for avascular necrosis in 24 patients. The average patient age at the time of operation was 43 years, and the average follow-up period was 4.6 years. Using a modified Hospital for Special Surgery hip rating system, the results were excellent in eight hips, good in seven, fair in eight, and poor in eight. Eight hips had residual pain despite a satisfactory rating. Four hips have required revision. There was a correlation between the patient's age and preoperative radiographic stage and the clinical result. Abduction-adduction weight-bearing radiographs showed that only 33% of the hips had significant inner-bearing motion. Superior acetabular cartilage narrowing or migration of the acetabular component was seen in 14 hips. Femoral component subsidence occurred in seven hips.