Intrahepatic cholangiocarcinoma (ICC) is a rare type of primary liver cancer that arises from intrahepatic bile ducts. Its etiopathogenesis has been considered to be independent of the presence of chronic viral hepatitis infections or cirrhosis. These factors, particularly the hepatitis C virus, have been reported to play a role in the development of cholangiocarcinoma in a few studies, with inconclusive results. We report 2 cases of ICC that presented with a background of hepatitis B virus (HBV) infection and discuss the possible pathophysiological relationships between ICC and HBV infection, with an emphasis on the x gene of HBV.