Forty-three prosthetic hip replacements (twenty-nine conventional total hip replacements and fourteen bipolar endoprosthetic replacements) were implanted between January 1971 and June 1982 in thirty-one patients who had systemic lupus erythematosus. All but four patients had stage-III or IV osteonecrosis of the femoral head. The median age at operation was forty-three years, and the median length of follow-up was fifty-seven months. Ratings were good or excellent for all but three total hip arthroplasties at a mean of sixty-six months of follow-up. Complications included delayed wound-healing (in approximately 15 per cent) and superficial wound infection (in approximately 10 per cent). The occurrence of these complications could not be correlated with the use of corticosteroids at the time of the operation. Twenty-five per cent of the patients, who were a mean of forty-three years old at operation, died less than five years postoperatively from complications related to systemic lupus erythematosus. Conclusions regarding the systemic effects of hip arthroplasty in patients with systemic lupus erythematosus could not be drawn on the basis of this study. Total hip arthroplasty uniformly provided a good or excellent result in patients of all ages who had systemic lupus erythematosus at a mean length of follow-up of sixty-six months. An increased incidence of local wound complications, which were unrelated to the use of corticosteroids, should be expected in patients with systemic lupus erythematosus who undergo prosthetic arthroplasty of the hip.