Intrabile duct tumor growth of hepatocellular carcinoma is an uncommon manifestation, but intraluminal bileduct hepatocellular carcinoma without primary hepatic parenchymal lesions is extremely rare. To our knowledge,only a few case reports have been published. We encountered two cases of primary hepatocellular carcinoma arisingin the bile duct; serum alpha-fetoprotein levels were within the normal limits. Both showed the followingcharacteristic radiologic features: 1) Cholangiography revealed filling defects within the dilated bile duct; 2)two-phase abdominal CT showed enhancement during the arterial-dominant phase and washout during the tissueequilibrium phase, as in typical HCC; and 3) hepatic arteriography revealed hypervascular tumor staining. Surgerywas performed and the resected specimen showed no detectable primary hepatic parenchymal mass; on the basis of thepathologic findings, intraluminal bile duct hepatocellular carcinoma was confirmed. We cautiously assume that thispeculiar type of HCC may arise primarily from bile duct mucosa.