Abstract:An endoscopic retrograde cholangiography (ERC) was performed in 303 patients before laparoscopic cholecystectory. The ERC was successful in 275 patients (90.8%). Common bile duct stones were diagnosed in 9 of 275 patients (3.3%). These had not been suspected on the basis of the clinical and laboratory data or ultrasonography results in 8 of them. An endoscopic papilotomy (EPT) was successful in all 9 patients with choledocholithiasis before laparoscopic cholecystectomy. Anatomical variations, such as origin of the cystic duct from the right or left hepatic duct and an accessory bile duct, were detected in 6 patients (2.2%). Preoperative ERC proved useful in determining the biliary anatomy or detecting unsuspected stones. (Dig Endosc 1994; 6 : 24–2