Obsturctive jaundice due to hepatocellular carcinoma in an extrahepatic bile duct, without a mass lesion in the liver parenchyma, is extremely rare. We experienced two cases of primary hepatocellular carcinoma arising from an extrahepatic bile duct: one in 1 53-uear-old man whose $alpha$-fetoprotein value was 800 ng/ml, and another in a 39-year-old woman, in whom mass lesion was found to be attached to an extrahepatic bile duct. These tumors had a well-marginated sausage-like shape on CT and US, and the contrast media passed freely along their margins on both PTC and ERCP. Recurrences of these were observed in the extrahepatic bile duct 6 and 2 months after surgery, respectively.