Background and objective: Bariatric surgery with Roux-en-Y gastric bypass (RYGB) is widely used to treat morbid obesity and present diagnostic and therapeutic challenges in patients with pancreatic and periampullary tumors. The aim of this study was to describe diagnostic tools and challenges in performing pancreatoduodenectomy (PD) on patients with altered anatomy after RYGB. Methods: Patients undergoing PD after RYGB from April 2015 to June 2022 at a tertiary referral center were identified. Preoperative workup, operative techniques, and outcomes were reviewed. A literature search was performed to identify articles reporting PD in post-RYGB patients. Results: Of a total of 788 PDs, six patients had previous RYGB. The majority were women (n = 5), and median age was 59 years. The patients most commonly presented with pain (50%) and jaundice (50%) with a median of 5.5 years after RYGB. The gastric remnant was resected in all cases, and reconstruction of the pancreatobiliary drainage was achieved using the distal part of the pre-existing pancreatobiliary limb in all patients. Median follow-up was 60 months. The Clavien–Dindo grade ⩾3 complications occurred in two patients (33.3%), and 90 days mortality occurred in one patient (16.6%). The literature search revealed 9 articles reporting a total of 122 cases, specifically addressing PD after RYGB. Conclusions: Reconstruction after PD in post-RYGB patients may be challenging. Resection of the gastric remnant and use of the pre-existing biliopancreatic limb may be a safe strategy, but surgeons should be prepared for other reconstruction options for creation of a new pancreatobiliary limb.