The patient was a 50-year-old man diagnosed as having a large type 3 advanced gastric cancer with para-aortic lymph node metastasis and with positive peritoneal cytology. We administered a combined systemic and intraperitoneal chemotherapy involving docetaxel, cisplatin, and S-1 (DCS). After 2 courses of treatment, the primary tumor and lymph nodes were significantly reduced in size, suggesting that this therapy induced a partial response (PR). No cancer cells were observed in the peritoneal cytology, and therefore, we performed curative total gastrectomy with para-aortic lymph node dissection. Histological findings revealed that there were no cancer cells in either the primary tumor or the lymph nodes, and pathological grading indicated that the resected lesions were grade 3. Adjuvant chemotherapy with S-1 was administered after surgery. At 18 months after surgery, the patient is still alive and free of disease.