Between March 1985 and June 1987, the first 100 liver transplantations at the Mayo Clinic were performed in 83 patients (primarily adults). The most frequent diagnoses were chronic active hepatitis (in 24 patients), primary sclerosing cholangitis (in 22), and primary biliary cirrhosis (in 20). The median operating time was 406 minutes, and the median usage of erythrocytes was 13.2 units. A venovenous bypass was used in all patients older than 10 years of age. Hepatic artery thrombosis occurred in 10% of the 100 transplants. A choledochocholedochostomy was done in 58 patients and a choledochojejunostomy in 25 patients. Revision of the biliary anastomosis was necessary in 9 of the 83 patients (11%). Rejection, diagnosed by clinical and histologic criteria, occurred in 50 patients (60%) and was treated with a corticosteroid bolus, followed by OKT3 (monoclonal antibody) treatment if necessary. Selective bowel decontamination helped prevent infections; only 16 bacteremias occurred, 1 of which was caused by a gram-negative organism. Fungal infections were rare. Cytomegalovirus infection occurred in 47 patients (57%). Of the 83 patients, 16 required retransplantation, in 11 of whom graft rejection had occurred. One- and 2-year patient survival was 83% and 70%, respectively. Although problems still remain, liver transplantation is a reasonable option for patients with end-stage liver disease.