Hepatomegaly and abnormalities of serum liver tests are common problems in patients with acquired immune deficiency syndrome. Opportunist infections (Mycobacterium avium-intracellulare and cytomegalovirus) and neoplasms (lymphoma, Kaposi's sarcoma) are among the most prevalent hepatic lesions in AIDS. Although Kupffer cells and endothelial cells are potential sites of human immunodeficiency virus 1 (HIV-1) infection, current studies do not indicate that the liver is a major reservoir for this virus. Drug hepatotoxicity, multimicrobial infections of the biliary tree resembling sclerosing cholangitis and a variety of nonspecific hepatic changes should be considered in evaluating AIDS patients or HIV-1-infected patients with evidence of liver dysfunction.