BACKGROUND Current guidelines recommend not performing papillary large balloon dilation in patients with nondilated distal bile ducts. AIM To assess the feasibility of balloon dilation to remove difficult stones in patients with nondilated distal bile ducts. METHODS Data from 1289 endoscopic retrograde cholangiopancreatography (ERCP) procedures were obtained from two prospective studies. While 258 cases had difficult stones (> 1 cm, multiple > 8, impacted, or having a thin distal duct), 191 underwent biliary dilation up to 15 mm after endoscopic sphincterotomy. Cholangiographies of these cases were retrospectively reviewed in order to classify the distal bile duct and both the stone size and number. Primary outcomes were clearance rate at first ERCP and complications. RESULTS Of the 191 patients (122 women and 69 men; mean age: 60 years) who underwent biliary dilation for difficult stones, 113 (59%) had a nondilated or tapered distal duct. Patients with a dilated distal duct were older than those with nondilated distal ducts (mean 68 and 52 years of age, respectively; P < 0.05), had more stones (median 4 and 2 stones per patient, respectively; P < 0.05), and had less need for additional mechanical lithotripsy (6.4% vs 25%, respectively; P < 0.05). Clearance rate at first ERCP was comparable between patients with a dilated (73/78; 94%) and nondilated distal ducts (103/113; 91%). Procedures were faster in patients with a dilated distal duct (mean 17 vs 24 min, respectively; P < 0.005). Complications were similar in both groups (6.4% vs 7.1%, respectively). CONCLUSION Large balloon dilation for difficult stones is feasible in patients with a nondilated or even tapered distal duct.