A 64-year-old male visited our hospital with complaints of epigastric pain. Computed tomography (CT) showed gastric cancer with extensive paraaortic lymph node metastasis. We decided that a curative operation was impossible, and administered the following chemotherapy. After 120 mg/day of TS-1 was orally administered for 3 weeks followed by 2 drug-free weeks with 90 mg of CDDP was administered intravenously on day 8, CT showed a 90.6% reduction in the paraaortic lymph node metastasis. No serious adverse reaction was observed. After 2 courses of this chemotherapy, surgery was performed after informed consent was obtained from the patient. Histrogical result showed PR. The patient is now healthy and no sign of recurrence has been observed. TS-1/CDDP therapy is useful for advanced gastric cancer.