Diffuse eosinophilic gastroenteritis is a rare disease on which only 120 cases in Western countries and 21 cases in Japan have been reported until 1983. This report describes a case of this disease, who was 50-year-old male with a chief complaint of abdominal fullness. Eosinophilia was not observed in the peripheral blood but a high level of IgE, iron deficient anemia and hypoproteinemia were detected. Upper GI series revealed circumferential irregularity and stiffness of the gastric wall from the fornix to the lower portion of the gastric body. Endoscopic study showed hyperplasia, tortuosity of mucosal fold and irregularly shaped ulcerations. Pathological diagnosis was not obtained by the histological examination of biopsied specimen and the total gastrectomy was performed. Perigastric adhesion to the left-diaphragma, pancreas, transverse colon and swelling of the regional lymphnodes were observed. Histological study showed diffuse infiltration of eosinophils in all layers especially in the submucosal layer, edema in the submucosa and partial granulomatous change. Cases like this involving almost the whole stomach and marked granulomatous change, are very rare and the present case was regarded to correspond with allergic granulomatosis proposed by Churg and Strauss.