A 44-year-old Japanese man was diagnosed to have Zollinger-Ellison syndrome. His main complaint was anemia due to gastrointestinal bleeding. After performing gastrointestinal endoscopy, duodenal ulcers were found located in the posterior wall of the duodenal bulbus. Three months before presentation, he had undergone surgery at our hospital due to acute bleeding pancreatitis. A case of Zollinger-Ellison syndrome with acute bleeding pancreatitis is rare, and there have so far been few reports of such cases in the English medical literature.