AIMS--To investigate the histopathological changes in the livers of patients undergoing cholecystectomy and to relate these changes to the underlying biliary tract pathology. METHODS--Liver changes in 67 patients undergoing cholecystectomy were investigated. Sixty three had gall stones, one cholesterolosis only, and there were three cases of acute acalculous cholecystitis. RESULTS--Only 34% of the patients had completely normal liver biopsy specimens. The most clinically important pathology was found in 11 of the 14 patients with choledocholithiasis: three of these had cholangitis and eight had features of large bile duct obstruction (four also had chronic cholestasis and portal-portal linking fibrosis). Non-specific reactive hepatitis was the most common abnormality in the remaining 53 patients with cholecystitis alone, and was found in 18. A further four patients had chronic cholestasis without fibrosis and early primary biliary cirrhosis was a coincidental finding in another. Clinical symptoms were poorly correlated with gall bladder and liver pathology apart from an association between jaundice and choledocholithiasis. Liver function tests of obstructive pattern were noted in 23 of 58 patients, most of whom had choledocholithiasis or non-specific reactive hepatitis. Bile cultures were positive in 10 of 42 patients, predominantly in cases of cholangitis and acute cholecystitis. CONCLUSIONS--Cholangitis and extensive fibrosis associated with large bile duct obstruction are common findings in patients with choledocholithiasis. The liver disease may progress to secondary biliary cirrhosis if the obstruction is not relieved, emphasising the need for early surgery. A peroperative liver biopsy may be useful to exclude cirrhosis in these patients, but is unlikely to be informative in those with cholecystitis alone.