A 68-year-old man was admitted to another hospital because of progressive weight decrease and appetite loss. Endoscopic examination revealed type 4 advanced gastric cancer at the upper body of the stomach. In February, 2003, he patient had probe laparotomy because there was a small amount of ascites in his peritoneal cavity, and intraoperative washing cytology revealed cancer cells in ascites.Subsequently, we started chemotherapy using S-1 and CPT-11. S-1 at a dose of 100 mg/day was orally administered for 2 weeks, and CPT-11 at a dose of 90 mg/body was intravenously administered once a week for 2 weeks followed by a 2-week drug-free period as 1 course. After 7 courses of the chemotherapy, the main lesion endoscopically vanished.Subsequently, the patient underwent curative total gastrectomy together with D2 lymph node dissection. Intraoperative cytology revealed no cancer cells, and histological examination of the primary lesion showed cancer cells invading the subserosa with no metastasis to any dissected lymph nodes. This therapy induced Grade 2 effect on cancer cells.Postoperatively, only S-1 was administered to the patient, who has remained alive with no recurrence for 4 years as of January, 2007.