In patients with hepatobiliary diseases, considerable amounts of sulfated and glucuronidated bile acids are excreted in urine. Information on the biliary excretion of these compounds is lacking. We used an intestinal perfusion method to determine the biliary excretion of sulfated and glucuronidated bile acids in eight patients with alcoholic cirrhosis and moderately severe cholestasis and compared results with urinary excretion rates. In bile, the patients excreted 508.7 μmoles per hr (mean) nonsulfated, nonglucuronidated bile acids, 8.1 μmoles per hr sulfated bile acids and 4.0 μmoles per hr glucuronidated bile acids. In urine, these patients excreted 0.27 μmoles per hr nonsulfated, nonglucuronidated bile acids, 0.88 μmoles per hr sulfated bile acids and 0.02 μmoles per hr glucuronidated bile acids. Sulfates and glucuronides of mono-, di- and trihydroxy bile acids were detected in urine and bile. In urine, tetrahydroxy bile acids were only excreted as nonsulfated and nonglucuronidated forms. The bile:urine excretion ratio of sulfated bile acids was 9:1 and of glucuronidated bile acids was 226:1. In alcoholic cirrhosis with cholestasis, biliary excretion is an important excretory route of sulfated and glucuronidated bile acids.