Introduction: Marginal ulcers after gastric bypass develops at the margins of gastrojejunostomy, mainly on the jejunal side. Potential risk factors include NSAIDs, Helicobacter pylori infection, smoking, and alcohol. We aim to share experience in our center in the management of perforated marginal ulcers after Roux-en-Y gastric bypass (RYGB) and one-anastomosis gastric bypass (OAGB). Patients and Methods: Between June 2021 and June 2024, data of all patients who had perforated marginal ulcers after OAGB or RYGB performed at Ain Shams University, Bariatric Surgery Department were collected. We included morbidly obese patients above 18 years old with perforated marginal ulcers after primary OAGB or RYGB. Results: In this study, 378 patients were included. Of them, 252 patients had OAGB with a mean age of 39.1 +/- 6.8. The remaining 126 patients had RYGB with a mean age of 39.9 +/- 4.6. The overall incidence of perforated marginal ulcer is 4.4%. The incidence of perforated marginal ulcer after OAGB is 3.1%, while that after RYGB is 7.1%. Eight patients had perforated marginal ulcers after OAGB. Of them, five patients had revision to RYGB. Three patients were managed surgically with exploration and omental patch repair. Nine patients had perforated marginal ulcers after RYGB. Six patients were managed surgically with exploration and omental patch repair. Three patients were managed by revision of gastrojejunostomy. Conclusion: The overall incidence of perforated marginal ulcer is 4.4%. The incidence of marginal ulcer after OAGB is 3.1%, while that after RYGB is 7.1%. Management options after diagnosis of perforated marginal ulcer are sufficient, but few prophylactic measures exist.