The aim of this work was to evaluate the opportunistic diseases and the cause of death of AIDS patients who were submitted to autopsy. We included all AIDS patients submitted to autopsy at a reference hospital of a medical school in São Paulo, Brazil, during the period of 1993 to 2000. Out of 1,478 autopsy cases in this period, 92 patients (6.22%) had the previously confirmed diagnosis of AIDS. Sixty-nine patients (75%) were men ranging in age from 19 to 68 years (mean 34.8). Eighty-five patients (92.4%) died due to infectious diseases, while only two died of neoplasia. Forty-four (48%) patients died from pulmonary infection, 14 (15%) from sepsis, 14 (15%) from disseminated mycobacteriosis, and six (7%) from Central Nervous System (CNS) infection. The opportunistic diseases found were mycobacteriosis (n = 25), Pneumocystis carinii infection (n = 16), Cytomegalovirus infection (n = 17), toxoplasmosis (8 CNS cases), candida sp infection (n = 12), histoplasmosis (n = 5), cryptococcus (n = 4), and one case of blastomycosis in the lung. Most of our AIDS patients are dying of infectious and opportunistic diseases that are not always diagnosed during their lifetime.