In infants and children, the effect of heart failure and/or cyanotic heart disease on the liver has not been well documented, nor has there been any comparison between the degree of liver dysfunction and hemodynamic factors. Sixty-five patients with cardiovascular abnormalities were examined. Hepatic function, as indicated by laboratory data and histologic liver studies, was compared with the following categories of cardiovascular dysfunction: hypoxemia, systemic venous congestion, and low cardiac output. If any one of these factors was present, or any combination, abnormalities of liver function were usually noted. Patients with both hypoxemia and systemic venous congestion had marked hepatic dysfunction. Those with low cardiac output had the most severe abnormalities. Serial studies indicated that liver function correlated with cardiac status.