Few patients with osteonecrosis that complicates human immunodeficiency virus (HIV) infection have been reported. We describe 5 patients whose symptoms of osteonecrosis developed with viral suppression and improvement in CD4 lymphocyte counts as a result of antiretroviral therapy. In addition, we review previously reported cases. The mean patient age was 35 years, and HIV was the sole risk factor in only 33%. Eighteen patients (55%) were receiving antiretroviral treatment when osteonecrosis was diagnosed. For 16 patients whose CD4 lymphocyte counts were reported, the mean CD4 count was 350 cells/mm(3). In 10 of these patients, the occurrence or worsening of symptoms of osteonecrosis appeared to be related to successful antiretroviral therapy. We conclude that osteonecrosis is an emerging manifestation of HIV infection and that it may be either a consequence of immunologic and virologic improvement resulting from antiretroviral therapy or a complication caused by the drugs themselves.