ABSTRACT— Of 20 patients with alcoholic liver cirrhosis and a superimposed episode of acute viral hepatitis, 12 developed hepatic encephalopathy or ascites or both. Four died of hepatic failure. Seventeen patients had received blood transfusions within 6 months before the acute hepatitic episode. Two patients were HBsAg-positive; the other 18 were presumptively diagnosed as having non-A, non-B hepatitis. However, hepatitis A virus infection was excluded in only three of the 18 patients. Histologic examination performed in 13 cases disclosed necrotizing inflammatory activity, which is commonly observed in acute viral hepatitis. The distinctive histologic feature was a meager regenerating activity. We conclude that patients with alcoholic cirrhosis complicated by acute viral hepatitis frequently develop hepatic failure and have a high fatality rate (20% in our series).