During 29 years from 1953 through 1981, 224 patients with congenital biliary atresia were treated and 200 of them underwent corrective operation at the Second Department of Surgery, Tohoku University Hospital. With the advance of surgical techniques and early diagnosis of biliary atresia, the rate of jaundice disappearance improved from the initial 15 per cent to the recent 69 per cent. Important factors contributing to the improvement of operative results included (1) an early operation, preferably within 60 days after birth, (2) a precise dissection and adequate transection of the porta hepatis, (3) prevention of post-operative cholangitis and (4) reoperation if indicated. Delayed operation and occurrence of post-operative cholangitis affected not only immediate but also long term operative results. Although, nearly all the patients with biliary atresia had portal hypertension at the time of surgery, the portal vein pressure decreased after successful operation, mainly due to improvement in portal venous circulation of the liver. It is considered from recent operative results that more than 80 per cent of patients with biliary atresia can be cured when an adequate corrective operation is carried out before 60 days of age and post-operative cholangitis is prevented.