Disseminated Pneumocystis carinii infection with hepatic involvement in a patient with the acquired immune deficiency syndrome. Extrapulmonary infection with Pneumocystis carinii (P. carinii) in AIDS patients is uncommon, and is often described only at postmortem examination. Although most antemortem cases involve spread to the bone marrow or spleen, P. carinii involvement of other organs has only recently been described. Despite the frequency of liver enzyme abnormalities in AIDS patients with a history of P. carinii pneumonia, P. carinii has been observed only rarely in the liver. We present a well-documented case of P. carinii involving the liver in an AIDS patient with P. carinii pneumonia and progressive liver enzyme abnormalities. We suggest that P. carinii infection should be considered in the differential diagnosis of AIDS-related liver disease. 