We report the case of a 49-year-old caucasian woman, in whom an endocrine tumor arising in gastric heterotopic pancreas was diagnosed. The patient was treated surgically with a gastric wedge resection. Heterotopic pancreas is a benign anatomic condition, probably widely underdiagnosed because usually asymptomatic. The malignant transformation of aberrant pancreas is very rare and almost always in adenocarcinoma. The endocrine tumors developed in heterotopic pancreas are exceedingly rare. Of our knowledge, only four cases have been published and only one case in the gastric location similar to this reported case.