We have performed chemoradiation with S-1 and low-dose CDDP as an initial treatment for 27 patients with incurable or unresectable highly advanced gastric cancer since 2002. Twelve out of 27 patients received combination chemotherapy of S-1 and CPT-11 as the second-line chemotherapy. On this regimen, S-1 was administered orally at a dose of 80 mg-120 mg daily, and CPT-11 at a dose of 60 mg/m(2) once in 2 or 3 weeks for outpatients. Clinical effects after therapy showed a response rate of 30.0%. Considering the prognostic outcome of the regimen, the one-year survival rate of the therapy was 66.7%, and the median survival time was more than 1 year, suggesting second-line chemotherapy will be one of the beneficial regimens in gastric cancer patients. Although 4 patients showed grade 3 bone marrow suppression (33.3%), they were all able to continue the therapy, after recovering from toxicity by means of G-CSF and/ or cessation of chemotherapy. The incidence and level of toxicity accompanying subjective symptoms, however, were relatively low, and the regimen was useful as an outpatient treatment maintaining good quality of life and improving their prognosis. Treatment with an appropriate regimen at an appropriate time will enable these patients to have good quality of life and survival.