A 70-year-old man was admitted to our hospital with obstructive jaundice. Computed tomography revealed a tumor in the left intrahepatic bile duct extending to the common bile duct without any significant lesions in the liver. Cholangiography showed a filling defect due to an intraductal tumor. Cytology of the bile juice was negative and tumor markers were carcinoembryonic antigen 5.7 ng/ml, carbohydrate antigen 19-9 49 U/ml, alpha-fetoprotein 9 ng/dl, and PIVKA-II 19 200 AU/ml. With a preoperative diagnosis of hilar bile duct carcinoma, a laparotomy was performed. The common bile duct was filled with a tumor and it extended into the bilateral intrahepatic bile ducts. The intraductal tumor was removed together with the extrahepatic bile ducts. An intraoperative histological examination of the tumor showed a well-differentiated hepatocellular carcinoma. No lesions were detected in the liver by ultrasonography, palpation during the operation, or a computed tomography scan after the operation. At 1 year postoperatively, no recurrence has been seen in this patient.