Endoscopic sphincterotomy (ES) is a well-established standard method for treating common bile duct stones. However, biliary sphincter function is impaired after the treatment, and this may influence the long-term outcomes. In this study, we aimed to compare the long-term outcomes after ES with those after endoscopic papillary balloon dilation (EPBD) because the latter procedure is expected to preserve biliary sphincter function better than ES.A prospective follow-up of the original cohort in a previously randomized, controlled trial to compare the early outcomes after ES and EPBD.Eleven centers, including 6 clinical practices and 5 academic institutions.A total of 282 patients with common bile duct stones were randomly selected to undergo ES (n = 144) or EPBD (n = 138) in the previous study.ES or EPBD.Complications after ES or EPBD occurring during long-term follow-up.The patients were followed up annually after the treatment. The median duration of the follow-up was 6.7 years. Morbidity was observed in 36 (25.0%) and 14 (10.1%) of the patients who underwent ES and EPBD, respectively (P = .0016). Kaplan-Meier analysis revealed a significantly higher incidence of biliary complications in the ES group than in the EPBD group (P = .0011). Multivariate analysis showed that ES, periampullary diverticulum, and in situ gallbladder stones were independent risk factors for stone recurrence.During long-term follow-up, patients who underwent ES had significantly more biliary complications than those who underwent EPBD. The biliary sphincter dysfunction after ES results in additional late complications.