A man in his 60s was referred to our institution for the evaluation of a gastric neuroendocrine tumor (G-NET) located in the fornix and that measured 13mm in size. Blood test results revealed hypergastrinemia (up to 3376pg/ml). Additional tests, including esophagogastroduodenoscopy, computed tomography, and intragastric pH monitoring, indicated that hypergastrinemia was not associated with type A autoimmune gastritis or gastrinoma. The patient was positive for the immunoglobulin G antibody against Helicobacter pylori, suggesting type B chronic atrophic gastritis as the cause for the condition. This report describes a rare case of G-NET with hypergastrinemia following type B chronic atrophic gastritis. Evaluation of similar cases is necessary to determine if H. pylori-associated chronic atrophic gastritis is frequently associated with G-NET.