The patient was a 61-year-old man who was referred to our hospital with a complaint of epigastric pain. Upper gastrointestinal endoscopy and X-ray examination of the stomach revealed type 3 cancer in the gastric antrum, extending to the middle body. It was about 9 cm in diameter, and the biopsy specimen revealed moderately differentiated tubular adenocarcinoma. Abdominal CT scan showed marked enlargement of No. 3 lymph nodes along the lesser curvature of the stomach. Examination of the blood showed a hemoglobin of 10.2 g/dl, CEA 5.8 ng/ml, CA19-9 330.5 U/ml. For this gastric cancer, clinical Stage IIIA (cT3N1HOPOMO), neoadjuvant chemotherapy with TS-1/CDDP was planned. TS-1 (120 mg/day) was orally administered for 3 weeks followed by a drug-free-2-week period as the first course, and 93 mg (60 mg/m2) of CDDP administered by intravenous drip on day 8. There were grade 2 nausea and grade 3 appetite loss by intravenous administration of CDDP in the second course. An upper GI series revealed 33% reduction of gastric cancer, and laboratory studies CEA and CA 19-9 showed normal values. One month after the second course of chemotherapy, total gastrectomy, splenectomy and lymph node dissection D2 were performed. The pathological specimens showed no cancer cells in the surgically obtained stomach and lymph nodes, so the histological effect was Grade 3. The postoperative course was satisfactory, and he now attends outpatient department without any findings of recurrence 12 months after the operation. TS-1/CDDP chemotherapy produced a high response in this case, and it may be useful as neoadjuvant chemotherapy for advanced gastric cancer.