We report the case of an 18-year-old man, with no previous medical history, presenting with recurrent hemorrhagic duodenal ulcers revealing a Zollinger-Ellison syndrome. The initial diagnosis of sporadic gastrinoma of the antrum associated with satellite lymph nodes led to surgical treatment. The evolution of clinical and secretory tests associated with the outbreak of a primary hyperparathyroïdism demonstrated that the patient had a type I multiple endocrine neoplasia. To our knowledge, this is the first described case of primitive gastrinoma of the antrum occurring in a type I multiple endocrine neoplasia.