Objective To study the feasibility and outcome of preoperative endoscopic retrograde cholangiopancreatography (ERCP) in elderly patients undergoing endoscopic extracton of large common bile duct stones.Methods Forty elderly patients (age range: 70-90 years old) with large (>20 mm) common bile duct stones underwent preoperative ERCP to visualize the stones and assess the difficulty of extraction.Endoscopic sphincterotomy (EST) and endoscopic mechanical lithotripsy (EML) were used on all patients to extract the stones.Endoscopic nasobiliary drainage or endoscopic retrograde biliary drainage (ERBD) was applied according to the specific circumstances of each patient.Postoperative therapy included antibiotics and antacids.Measurements of blood amylase and trypsin inhibitor was measured to monitor patient recovery status.Results Bile stones were successfully extracted from 37 of the 40 cases, giving a success rate of 92.5%.Nine of these 37 cases required a second operation to retrieve the stone basket or balloon (n=6) or to replace the original stent (n=3) .Six patients developed postoperative complications (pancreatitis, n=4;delayed incision hemorrhage, n=2) , but all were cured with standard medical therapies.None of the patients experienced severe complications, such as death, bowel perforation, or bowel tearing.Conclusion ERCP is safe and efficient for use with endoscopic surgical extraction of large common bile duct stones in elderly patients.ERCP is recommended for treatment of these patients.