The cases of two brothers with intrahepatic arterio-venous shunt causing hyperdynamic circulation in hereditary hemorrhagic telangiectasia are presented. There was a strong family history of fatal liver involvement in all members of the previous generation. The first patient had embolization of the right hepatic artery with symptomatic relief, but developed cirrhosis with portal hypertension seven years later. The second patient developed cirrhosis with portal hypertension, and died following rupture of esophageal varices, within a year. It is suggested not only that hereditary hemorrhagic telangiectasia is transmitted as a dominant trait, but that there is also a hereditary transmission of hepatic involvement in this disease.