Two patients with advanced gastric cancer who underwent gastrectomy and pathological examination were both diagnosed as having Stage IV gastric cancer with distant lymph-node metastases and peritoneal dissemination, respectively. The patients received S-1 and low-dose CDDP in combination therapy after reduction surgery. Each treatment course consisted of S-1 100 mg/body oral administration for 3 weeks and intravenous administration of CDDP at a dose of 25 mg/m(2) on days 7, 14 and 21. The course repeated after a two-week rest period, and the treatment was repeated every five weeks. After three courses of treatment, both patients received S-1 100 mg/body for 2 weeks on and 2 weeks off as long as possible. They remain alive 15 and 12 months after initial treatment, respectively, without any sign of recurrence. The patients did not experience grade 3 or more adverse events and received this regimen as an outpatient. These results suggest that combination therapy with S-1 and low-dose CDDP is effective against advanced gastric cancer.