A 73-year-old former soldier in whom a deposition of thorotrast had been detected 7 years previously was admitted to our hospital because of high fever and epigastric pain. He had been well with standard liver function tests within the normal range until 4 months before admission. Laboratory examination on admission showed marked abnormalities in the liver function tests and an elevated level of CEA. Abdominal ultrasonography and computerized tomography, which had shown no space-occupying lesion in the liver one year earlier, revealed an abnormal mass in the right hepatic lobe. Angiographic examination revealed low vascularity and encasement of the intrahepatic artery. The disease was diagnosed as thorotrast-induced cholangiocarcinoma. Despite chemotherapy, the patient's condition worsened rapidly and he died on the 78th day after admission. At autopsy, the primary tumor in the right hepatic lobe and metastatic nodular tumors throughout the liver were found. The histological diagnosis was cholangiocarcinoma. Thorotrast-induced liver cancers are inclined to grow rapidly, so early diagnosis of liver tumor accompanied by thorotrastosis is very difficult, as in this case. Repeated examinations at frequent intervals are required for early diagnosis.