A 62-year-old woman was admitted for anemia. An endoscopic examination revealed type 2 cancer from the upper body of the stomach to the antrum, and abdominal CT scan demonstrated enlarged abdominal paraaortic lymph nodes. The preoperative diagnosis was cStage IV gastric cancer (cT 3, cN 3, cH 0, cP 0, cM 0). Since a curative operation was deemed impossible, we conducted neoadjuvant chemotherapy using TS-1 plus cisplatin (CDDP) for downstaging. TS-1( 100 mg/day) was orally administered for 3 weeks,and CDDP (60 mg/m2) was given intravenously on day 8. Appetite loss of grade 3 and erythropenia of grade 1 were observed. After two courses of chemotherapy the primary lesion and the paraaortic lymph nodes were significantly reduced in size. She was judged as clinical PR, followed by distal gastrectomy and lymph node dissection, resulting in curability A. Histopathologically, the tumor was diagnosed as adenosquamous carcinoma of the stomach with lymph node metastasis at only No.3. This case suggests that neoadjuvant chemotherapy using TS-1 plus CDDP is effective for advanced gastric adenosquamous carcinoma with massive lymph node metastases.