From 1966 through 1985, a total of 640 patients received 739 renal transplants at a single center transplantation program. Of 245 total deaths, a slide and chart review of all 116 autopsied cases (47%) identified the major causes of death as pneumonia (n = 43), sepsis (n = 32), hemorrhage (n = 15), peritonitis (n = 11), meningitis (n = 7), and pulmonary embolism (n = 5). Eighty-five (73.3%) of these patients died of complications directly associated with immunosuppression, almost all (n = 82) as a result of infection. Organisms most frequently identified at death were gram-negative bacilli (n = 72), Candida species (n = 23), cytomegalovirus (n = 17), enterococcus (n = 14), Staphylococcus aureus (n = 11), Aspergillus species (n = 10), Pneumocystis carinii (n = 5), and mycobacteria (n = 5). Significant associations were found between bolus steroid antirejection therapy and infection with Aspergillus cytomegalovirus. Diabetics had a higher incidence of fungal infections and bowel perforation than nondiabetics. During this 20-year period, overall one-year actual patient survival rates for the four respective five-year intervals increased dramatically (69.9%, 68.2%, 83.3%, and 91.8%), but the normalized death rate showed a smaller decrease for infectious vs noninfectious causes.