OBJECTIVE to study the biochemical composition of cystic and hepatic bile in patients with different forms of viral hepatitis. METHODS Four hundred and fifty-seven patients with different forms of viral hepatitis were examined. The concentration and debit of cholic acid (CA), total cholesterol, total bilirubin, phospholipids, calcium, and C-reactive protein were determined by a bile biochemical study. Cholate-cholesterol and phospholipid-cholesterol ratios were simultaneously calculated for each bile portion. RESULTS CA levels and cholate-cholesterol ratios were significantly decreased in all patients with viral hepatitis. The findings suggest that duodenal digestion was impaired, CA secretion was lowered and the majority of patients with viral hepatitis had biliary insufficiency. CONCLUSIONS Stepwise chromatic duodenal intubation should be used, by making a biochemical study of bile portions and calculating the total debit of bile components secreted per hour after administration of a stimulus, in order to make a complex diagnosis of exocrine function of the liver in patients with viral hepatitis.