Hepatocellular carcinoma has been commonly associated with multiple etiologic factors including hepatitis B and C, alcoholic liver disease, and more rarely congenital metabolic liver diseases. 'Cardiac cirrhosis' is the cirrhosis resulting from prolonged passive liver venous congestion secondary to right-sided congestive heart failure; hepatocellular carcinoma is a rarely reported outcome. In this study we present two female patients with congenital heart defects treated with the Fontan procedure who survived into their third decade, and developed hepatocellular carcinoma in the setting of cardiac cirrhosis. The Fontan procedure diverts blood from the inferior vena cava and superior vena cava to the pulmonary arteries, thereby increasing survival in infants born with a single effective ventricle. As such patients live longer, however elevated pulmonary and right-sided heart pressures cause chronic passive liver congestion and eventual cardiac cirrhosis. The two patients in this study had no risk factors for hepatocellular carcinoma other than cardiac cirrhosis secondary to their prolonged survival after their Fontan procedure. In conclusion, we suggest that cardiac cirrhosis may be a risk factor for developing hepatocellular carcinoma and recommend close follow-up and hepatocellular carcinoma screening for patients with known right heart failure and passive hepatic congestion.