Risk factors for postoperative hepatic dysfunction were studied by measuring the change in the serum alanine aminotransferase (GPT). We studied 1,759 patients consecutively treated with surgery for various diseases of the lung, breast, esophagus, stomach, colon, rectum, liver, biliary tract, portal system and aorta in the Department of Surgery II, Kyushu University, Japan from 1985 to 1989. The multivariate analysis revealed that the independent risk factors for postoperative hepatic dysfunction were preexisting liver disease, surgical management of an esophageal cancer and halothane anesthesia.