A 44-year-old woman was treated with 60Co irradiation (total dose, 6000 rads) focused on the right side porta hepatis under the diagnosis of cholangiocarcinoma in 1975. Seventeen years after the treatment, she was admitted to our institution because of dull pain at right hypochondriac region. Abdominal CT demonstrated an extreme hepatic atrophy and tumor mass in the right lobe of the liver. In November, 1991 right tri-segmentectomy was performed under the diagnosis of hepatocellular carcinoma. Laparotomy revealed the extreme atrophy of the right lobe and associated hypertrophy of the left lobe of the liver. In this case radiation hepatitis occurred after irradiation to the liver and it was followed by the extreme hepatic atrophy as a long term effect of high dose irradiation on the liver.