Ninety patients with biliary atresia surviving more than 5 years were analysed with respect to late complications occurring after the age of 4 years. Thirty-five had complications including cholangitis, portal hypertension, hypersplenism, gastrointestinal bleeding, and esophageal varices. These complications occurred at various times. The background factors of late complications were past history of cholangitis soon after the operation, advanced age at operation, re-operation, high portal pressure at initial operation, and a long interval before disappearance of jaundice after surgery. These factors are mostly related to the first operation and its postoperative course. Therefore, we stress that late complications can be prevented by intensive treatment of the patient at the time of the first operation.