Laparoscopy is the preferred approach for cholecystectomy; however the indications for pre- versus postoperative endoscopic retrograde cholangiography (ERC) are still evolving. The records of patients who had ERC performed one month before (n=119) or after (n=35) laparoscopic or open cholecystectomy from January 1990 to August 1992 (period 1), and 66 patients who had preoperative ERC from November 1995 to October 1996 (period 2) are reviewed. ERC indications, findings and outcomes were reviewed, and trends in the use of preoperative ERC from 1990 to 1996 were sought. Between periods 1 and 2 the yield of preoperative ERC increased from 36% to 58% (P<0.01). The use of preoperative ERC for the indication of abnormal liver enzymes declined (P<0.05), while the yield increased (25% versus 61%, P<0.01). Both the use of ERC and the yield remained stable for other indications. ERC was felt to have changed the surgical approach in 5% of patients. Primary indications for postoperative ERC (n=35) included abnormal intraoperative cholangiography (43%), liver function test abnormalities (23%) and recurrence of preoperative symptoms (14%); stones were found in 60%, 50% and 20% of patients with these indications, respectively. Overall, 46% of postoperative studies revealed duct stones. The roles for pre- and postoperative ERC are changing and depend greatly on the relative laparoscopic and endoscopic expertise at a given institution.