Background and aims: large balloon sphincteroplasty (LBS) associated with sphincterotomy (ES) has gained acceptance as a useful tool in extracting difficult bile duct stones. Our purpose was to evaluate the efficacy and safety of LBS with balloons ≥ 10 mm in clinical practice setting.Patients and methods: unicentre prospective study in a tertiary care hospital. All patients who underwent LBS associated with ES between July 2007 and March 2011 were included prospectively in a database recording clinical aspects, procedure data, outcome and complications.Success is the main outcome defined as complete stone removal documented by absence of any filling defect during a final occlusion cholangiogram and absence of clinical or radiological findings after the ERCP consistent with remaining stones. Complications as pancreatitis, cholangitis, post-ERCP bleeding, perforation and others were also measured.Results: one hundred twenty procedures were made in 109 patients with balloons ranging from 10 to 20 mm. Success rate was 91% in the first attempt and 96.7% after two procedures. Mechanical lithotripsy was only needed in one case (0.8%). Complication rate was 4.2% due to five cases of post-ERCP bleeding in high risk patients.Conclusion: large balloon sphincteroplasty associated to sphincterotomy in clinical practice is a very effective and safe technique.