Two case studies of eosinophilic gastritis studied by the Pathology Department of the Hospital Central de San Luis Potosi are presented. Based on these cases, the clinical pathological forms of the entity are analized together with the classification and etiopathology, from which it is considered a late allergic or hipersensitive reaction to foreign proteins. Therefore, it is essentially different from the neoplastic, histiocitic, eosinophilic granuloma of the bone.