The objective of the present study was to analyze the effects of different factors impacting the caliber of the common bile duct (CBD) and a comparison of maximum extrahepatic bile duct caliber in patients with and without a history of cholecystectomy. A retrospective data analysis was undertaken of 8534 patients (4480 females; 4054 males; average age: 59.2±18.0 years) with sonographic documentation of bile duct caliber. Maximum intra- and extrahepatic bile duct diameters were studied.