BackgroundEndoscopic retrograde cholangiopancreatography (ERCP) is technically challenging in patients with Roux-en-Y gastric bypass (RYGB) due to altered anatomy. ObjectiveTo compare the procedural and clinical outcomes of 4 different ERCP techniques in RYGB patients. SettingAcademic tertiary referral center in the United States. MethodsA retrospective cohort study including patients with RYGB anatomy who underwent an ERCP between January 2015 and September 2020. We compared procedural success and adverse events (AEs) rates of balloon-assisted enteroscopy (BAE), gastrostomy-assisted ERCP (GAE), endoscopic ultrasound (EUS)-directed transgastric ERCP (EDGE), and rendezvous guidewire-assisted ERCP (RGA). ResultsSeventy-eight RYGB patients underwent a total of 132 ERCPs. The mean age was 60 ± 11.8 years, with female predominance (85.7%). The ERCP procedures performed were BAE (n = 64; 48.5%), GAE (n = 18; 13.7%), EDGE (n = 25; 18.9%), and RGA (n = 25; 18.9%), with overall procedure success rates of 64.1%, 100%, 89.5%, and 91.7%, respectively. All approaches were superior to BAE (GAE versus BAE, P = .003; EDGE versus BAE, P = .034; RGA versus BAE, P = .011). The overall AE rates were 10.9%, 11.1%, 15.8 %, and 25.0%, respectively. There was no statistical difference in AEs. There were also no differences in bleeding, post-ERCP pancreatitis, and perforation rates between the 4 approaches. ConclusionProcedure success was similar between GAE, RGA, and EDGE, but superior to BAE. AE rates were similar between approaches.