Patients undergoing orthotopic hepatic transplantation were studied with routinely available liver function studies and serial hepatic biopsies. Rejection was diagnosed only if confirmed histologically. Cyclosporine and a rapidly decreasing dose of corticosteroids were used for immunosuppression. Hepatic dysfunction suggesting rejection was seen in 22 instances, but acute rejection was diagnosed histologically in only 6 patients. The liver function studies used in these patients did not accurately distinguish rejection from other causes of hepatic dysfunction. We conclude that liver biopsy as performed in these patients is an accurate and safe means of assessing the adequacy of immunosuppression and minimizing the use of high dose corticosteroids.