Hepatocellular carcinoma has a great tendency to invade blood vessels, particularly the portal vein. Invasion into the biliary lumen has been considered to be a rather rare event. Ultrasonogram and endoscopic retrograde cholangiopancreatography of the patient, a 65-year-old man presenting with obstructive jaundice, revealed an obstructing mass at the common hepatic duct and dilatation of the intrahepatic bile ducts. Abdominal computed tomography and hepatic angiogram showed no abnormal mass and abnormal staining in the liver. Obstructive jaundice due to Klatskin's tumor was suspected preoperatively. During operation, although no tumor was palpable in the liver, an intraductal tumor measuring 3.5X3.0 cm was found in the common hepatic duct. Bile duct resection was performed in a patient. Histologically, the tumor, a hepatocellular carcinoma showing abundant eosinophilic cytoplasm, was structurally arranged in a solid and trabecular pattern. We report a case of hepatocellular carcinoma mainly presenting as Klatskin tumor.