One hundred twenty-nine adult patients who received an orthotopic liver transplantation and survived at least 24 hr after surgery were evaluated. During the period of follow-up, 48 of the 129 patients (37%) died. Only 40 of these 48 patients died at our institution and were included in this study. Seventeen of the 40 deaths (42.5%) occurred during the first month after orthotopic liver transplantation and 30 of the 40 deaths (75%) occurred during the first 60 days post-orthotopic liver transplantation. Death was related to infection in 21 cases (52.5%), to multiorgan failure in 8 (20%) and to uncontrollable rejection in 3 (7.6%). The remaining eight deaths (20%) were attributed to a variety of other causes. Eleven of the 21 deaths related to infection (52%) occurred during the first month after orthotopic liver transplantation. Bacterial sepsis was the leading cause of death and accounted for 17 of the 21 deaths (81%) in which infection was present at the time of death. The most frequently isolated bacteria were Pseudomonas and other enteric Gram-negative bacilli. Three patients had complete occlusion of the hepatic artery of the grafted liver. Six patients developed massive infarction of the liver despite patent vascular anastomoses. Histological signs of rejection were seen in 9 of the 31 patients autopsied (29%), but in only 3 of these (9.6%) was rejection the principal cause of death. The biliary anastomoses were patent in all 31 cases examined at autopsy.