Three common opportunistic infections in patients with the human immunodeficiency virus are being more accurately diagnosed and effectively treated as a result of recent advances. Toxoplasmosis may be prevented in some cases, and can be recognized and treated noninvasively in most cases. Cryptococcal therapy has been enhanced by successful development of oral azole therapy. Cytomegalovirus encephalitis is now an entity that can be diagnosed antemortem, and thus efforts to treat it can now be evaluated.