ObjectiveTo evaluate the efficacy and safety of endoscopic retrograde cholangiopancreatography (ERCP) for patients after Billroth Ⅱ gastrectomy. MethodsData of 67 patients after Billroth Ⅱ gastrectomy who underwent ERCP at endoscopic center of Xijing Hospital of Digestive Diseases from January 2013 to December 2018 were retrospectively analyzed. Patients were firstly divided into Braun-anastomosis group and non-Braun-anastomosis group. They were also divided into duodenoscopy group, conventional forward-viewing endoscopy group and balloon-assisted enteroscopy group according to endoscopic selection. The rates of ERCP success and adverse events were analyzed. ResultsA total of 82 ERCP procedures were performed on 67 patients. The cannulation success rate, diagnostic success rate, therapeutic success rate and ERCP success rate in patients after Billroth Ⅱ gastrectomy were 90.2% (74/82), 87.8% (65/74), 100.0% (65/65) and 79.3% (65/82), respectively. The ERCP success rates in patients with non-Braun-anastomosis and Braun-anastomosis were 79.7% (47/59) and 78.3% (18/23), respectively. The ERCP success rates of duodenoscopy group, conventional forward-viewing endoscopy group and balloon-assisted enteroscopy group were 93.8% (15/16), 76.2% (48/63) and 2/3, respectively. ERCP success rates of conventional forward-viewing endoscopy with and without transparent cap were 80.8% (42/52) and 54.5% (6/11), respectively. No adverse events occurred in any patient. ConclusionERCP after Billroth Ⅱ gastrectomy is effective and safe. Balloon-assisted enteroscopy can be an option after the failure of duodenoscopy and conventional forward-viewing endoscopy. ERCP success rate can probably be improved with the aid of transparent cap when conventional forward-viewing endoscope is used.