Serum total lipids, lipoprotein cholesterol, apolipoprotein A (Apo A) and liver function parameters have been investigated in patients with acute viral hepatitis and chronic liver disease. Hypertriglyceridaemia, absence of alpha and pre beta bands on the lipoprotein electrophoresis pattern, low level of Apo A, presence of abnormal lipoproteins (beta-VLDL and beta2-LP) were observed in the early phase of acute hepatitis. A positive correlation was found between Apo A and triglyceride bile acids, log total bilirubin, log SGPT. Lipoprotein abnormalities are probably due to low lecitin-cholesterol aciltransferasi activity. The reappearance of alpha lipoprotein and the increase of Apo A are sensitive indices of improvement of liver function. In chronic liver disease the levels of cholesterol and Apo A correlate with changes in the hepatocellular function.