BACKGROUND/OBJECTIVES: Performing endoscopic retrograde cholangiopancreatography (ERCP) in surgically altered gastrointestinal anatomy remains challenging, frequently necessitating the use of forward-viewing endoscopes. Given the challenge in endoscope selection based on the type of altered anatomy, the aim of this study was to examine ERCP success rates by specific endoscopes for different anatomy types. METHODS: This single-center retrospective study examined ERCPs performed in patients with surgically altered gastrointestinal anatomy during an 18-year period. Enteroscopy success, cannulation success, and intervention success rates were compared between the different anatomy and endoscope types. RESULTS: This study included a total of 334 adult patients (665 total ERCPs) with altered anatomy. The pediatric colonoscope was most frequently utilized (32.2%), and the majority of procedures were performed for biliary indications. Enteroscopy success was 82.2% in Roux-en-Y gastric bypass (RYGB), 97% in Billroth II, 91.5% in Whipple, and 93.2% in Roux-en-Y hepaticojejunostomy (RYHJ). Cannulation success was 90.5% in RYGB, 90.5% in Billroth II, 83.6% in Whipple, and 90.6% in RYHJ. Intervention success was 88.2% in Billroth II, 65.1% in RYGB, 81.6% in Whipple, and 87.5% in RYHJ. In patients with RYGB and RYHJ, SBE was utilized most frequently, with rotational enteroscopy having the highest success rates. The overall adverse event rate was 5.1%, with the majority of these being mild in severity. CONCLUSIONS: This large retrospective study found ERCP with forward-viewing endoscopes to be safe and effective for a variety of surgically altered anatomy types. Despite recent advances seen with endoscopic ultrasound-guided drainage procedures, this study advocates for ERCP as the initial approach for pancreaticobiliary access in surgically altered anatomy.