Gastric tuberculosis is quite rare and usually combined with pulmonary tuberculosis. Its diagnosis is so difficult as it is often unsuspected, We report a patient with gastric tuberculosis who presented with hematemesis in Korea, Upper endoscopy showed large, deep penetrating ulcer containing an exposed vessel and adherent clot in the body. Gastric biopsies revealed only chronic inflammation and no evidence of granuloma or malignancy. Diffuse mural thickening was noted on abdominal CT. The diagnosis was made postoperatively following gastrectomy for bleeding gastric ulcer. Microscopic examination of resected stomach showed peptic detritus and noncaseating granulomas. However, multiple caseating granulomas with Lagerhan's giant cells were found on the examination of lymph nodes. The patient was treated with antituberculous therapy for 12 months without any complications.