Much of the research into bile physiology during the past 12 months has dealt with some aspect of bile acid biosynthesis, including defects of cholesterol side-chain oxidation associated with clinical problems. A pharmacologic interest is illustrated by several papers dealing with “designer” bile acids, the second-messenger role of arachidonic acid oxidation products, and the effects of lipid-lowering agents on biliary chemistry. Each year our understanding of the diverse biologic activities of bile acids increases. This year is no exception, with new insights into the role of bile acids in milk digestion in the neonate and in the biliary excretion and intestinal absorption of ferrous iron. Despite further work on the mechanisms of bile acid-induced cytotoxicity and cytoprotection, there is little new information on the therapeutic efficacy of ursodeoxycholic acid in chronic liver disease.