We report a case of advanced gastric cancer successfully treated with preoperative S-1/Lentinan (LTN)chemotherapy followed by curative gastrectomy. The patient was a 75-year-old man with right hypochondralgia. Endoscopic examination revealed a huge type 2 gastric cancer in the middle body of the stomach. Abdominal computed tomography (CT) revealed multiple perigastric lymph node metastases and bulky para-aortic lymph node metastases. The clinical diagnosis was cT 4N3M1( LYM) with cStage IV. We thought a complete resection would be difficult, so he was treated with S-1( 80 mg/m2 day 1-28/q6w) and LTN (2 mg weekly) in May 2010. After 3 courses, the primary lesion was markedly reduced, and gastric endoscopic biopsy showed no malignant lesion. After 4 courses, abdominal CT showed no lymph node swelling at the perigastric and para-aortic areas. After 5 courses, distal gastrectomy with D2 lymphadenectomy was performed. The histological diagnosis was ypT2( MP) N0M0, Stage IB. Histological features of the primary tumor and lymph nodes were judged to be Grade 2 and Grade 3, respectively. After surgery, S-1/LTN treatment was continued for 1 year. During this period, there were no serious adverse events. The patient has been in good health without recurrence for 28 months after surgery.