A 65-year-old man was admitted to our hospital with nausea, vomiting and appetite loss. First upper endoscopic examination and X-ray examination showed a peptic ulcer and a pyloric stenosis. Fiberscope could not go through the pyloric ring. Computed tomography examination and biopsy showed no evidence of malignancy. Though we considered surgical resection of the stenosis at first, he could eat a staple food with therapy of proton pump inhibitor. So we followed up with upper endoscopic examinations. Second, third and forth upper endoscopic examinations showed no evidence of malignancy. Fifth upper endoscopic examination showed an ulcer scar on the pyloric ring and a 0-IIc carcinoma in the antral greater curvature. Distal gastrectomy with D2 lymph node dissection and B-II reconstruction. Pathologically, a mucosal carcinoma with no lymph node metastasis and U1-III peptic ulcer were diagnosed.