The authors set out to evaluate the use of the autopsy in an urban public teaching hospital setting during the AIDS era. Demographic and length of hospital stay data were obtained from weekly mortality review reports on all patients dying on the medicine service between 1/1/92 and 12/31/93. Clinical and autopsy diagnoses were compared for those patients who had autopsies. The autopsy rate was 16% (152/974). Significant, unsuspected diagnoses were found in 35% (53/152) of the cases, with infections, pulmonary emboli, and myocardial infarctions being most common. Human immunodeficiency virus-infected patients had a greater percentage of unsuspected findings (55%, 23/42), and many of these also were from an infectious etiology. The authors conclude that valuable, unsuspected information frequently can be obtained from autopsies in this clinical setting.