AbstractTo assess the significance of common bile duct dilatation in biliary lithiasis, we studied 3,802 patients who underwent surgery for biliary calculous disease. It has been shown that there is a higher incidence of common bile duct dilatation in patients of advanced age, in those with a long history of symptoms, and in those who have undergone previous biliary surgery. Furthermore, it has been noted that common bile duct dilatation is associated with a high incidence of bile infection of primary common bile duct stones and of pathological changes on the biliary tree histology. These findings support the view that common bile duct dilatation should be considered as an end result of advanced biliary tree disease and it may well predict a high potential for recurrent choledocholithiasis.