A 42-yr-old woman presented with multiple carcinoid tumors in her stomach and a markedly elevated serum gastrin level. Total gastrectomy was performed, and 22 small carcinoid tumors were found in the gastric fundus and body. A high serum gastrin level was revealed in the gastric drainage veins; still more gastrin was detected in the carcinoid tumors by the immunohistochemical method, and many secretory granules were found in the tumor cells with an electron microscope. The fundic gland showed marked atrophy, and there was some conglobation of endocrine cells (ECL cells). This case suggests a hypothetic sequence of anacidity due to atrophic gastritis----hypergastrinemia----proliferation of ECL cells----multiple carcinoids. A search of the Japanese literature revealed that 26 cases of multiple carcinoid tumors in the stomach have been reported so far, and most of them support this hypothesis.