Background: The utility and safety of endoscopic biliary orifice balloon dilation (EBD) for bile duct stone removal (with use of large-diameter balloons) after biliary endoscopic sphincterotomy (BES) is currently not well established.Objective: Our purpose was to evaluate the efficacy and complications of BES followed by >= 12 mm diameter EBD for bile duct stone removal.Design: Retrospective, multicenter series.Setting: Five ERCP referral centers in the United States.Patients and Interventions: Patients who underwent attempted removal of bile duct stones by BES followed by EBD with >= 12 mm diameter dilating balloons were identified by searching the prospectively recorded endoscopic databases from 1999 to 2007. Clinical parameters, endoscopic data, and outcomes were collected and analyzed.Results: One hundred three patients, mean age 70 +/- 17 years (range 23-98 years), with 56 (54%) women, underwent 107 procedures. Eleven patients (11%) had a prior history of acute pancreatitis. Pancreatogram was performed in 15 (14%) patients. Median stone size and median balloon diameter used was 13 mm. Complete stone removal in the first session of EBD was accomplished in 102 (95%) procedures, and mechanical lithotripsy was required in 29 (27%). Six patients (5.4%) had documented procedure-related complications including one patient with severe bleeding and one with severe cystic duct perforation. No acute pancreatitis occurred.Conclusion: EBD with a large-diameter balloon in conjunction with BES for bile duct stone removal is effective and relatively safe. This technique appears to be a reasonable alternative option when standard BES and basket or balloon sweep are inadequate to remove bile duct stones.