This review concern with recent results regarding interrelationships between serum lipoprotein and bile acid metabolism. First, changes in bile acid metabolism in primary hyperlipoproteinaemia type II and type IV are described. In addition, influences of lipid-lowering drugs such as sitosterol, cholestyramine/colestipol, neomycin, nicotinic acid, clofibrate and thyroxin on serum lipoproteins and biliary lipid metabolism are discussed. Changes in lipoprotein metabolism in disorders of bile acid metabolism and effects of primary and secundary bile acids on lipoprotein metabolism, hepatic cholesterol metabolism and intestinal cholesterol absorption are described. In the final discussion interrelationships between very low density lipoprotein - triglycerides and cholic acid metabolism as well as low density lipoprotein and chenodeoxycholic acid metabolism are stressed. The positive correlation between serum triglycerides and lithogenicity of bile is underlined and the possible significance of high density lipoprotein-cholesterol as precursor of biliary cholesterol is discussed.