A case of type 2 diabetic patient, a 67-year-old woman, with a large abscess of the gastric wall which seemed to be a primary lesion is described for the first time. Fortunately, patient was successfully treated with both the maintenance of a good glycemic control and systemic antibiotics without laparotomy or drainage. Thus, a tight glycemic control and awareness of this disease should be reemphasized, and this may improve the prognosis of this rare and fatal one, even a poorly-controlled diabetes.