Long-term complications following pancreaticoduodenectomy are rarely reported because of the poor longterm survival of these patients. Marginal ulcers can occur in both the short and long term, and they can become complicated by bleeding or perforation. Marginal ulcer with perforation is a rare incidence and only sparse literature evidence is available. Herein, we report on a patient who underwent pancreaticoduodenectomy 12 years ago for duodenal adenocarcinoma and was diagnosed to have perforation peritonitis. He underwent emergency laparotomy and lavage, and omental patch closure for marginal ulcer perforation at the gastrojejunostomy site. Truncal vagotomy and feeding jejunostomy were also done.