Serum cholesterol, triglyceride, total lipids and the lipoprotein pattern were studied in 169 cases chronic liver disease confirmed by biopsy. On the ground of the immunological and morphological results the patients were classified into five groups. In chronic persistent hepatitis no significant abnormality was found. In chronic aggressive hepatitis and in cirrhosis of the liver the serum cholesterol level was significantly reduced. In fatty infiltration of the liver the serum cholesterol, triglyceride and total lipid concentrations were significantly increased, as compared with the normal values and with the figures obtained in the cases of chronic inflammatory liver disease. In the cases of cirrhosis with additional diabetes the lipid values were likewise increased. In chronic aggressive hepatitis and in cirrhosis of the liver the levels of pre-beta and alpha lipoprotein were decreased, in fatty infiltration of the liver those of beta and pre-beta lipoprotein were increased.