We reviewed retrospectively 25 hip arthroplasties in 25 patients with sickle-cell haemoglobinopathy and osteonecrosis. The mean age of the ten women and 15 men at the onset of hip symptoms was 25 years, and at surgery 30 years (16 to 45); 66% had either SS or S-thal disease, 20% sickle-cell trait, and the remainder SC disease. The mean follow-up was 8.6 years (two to 18). Fourteen (40%) of the arthroplasties had been revised at a mean of 7.5 years after the primary procedure and nine other hips were either radiographically and/or symptomatically loose. The overall complication rate was 49% and the infection rate 20%. The risk-to-benefit ratio of hip arthroplasty in sickle-cell haemoglobinopathy is high.