A 79-year-old male was diagnosed as having a scirrhous cancer of the stomach. Carcinomatous peritonitis was suspected on abdominal CT examination and the CA19-9 showed a high level of 95 U/ml. The patient was treated with combined chemotherapy of TS-1 and CDDP. TS-1 (100 mg/day) was administered for 14 days followed by 14 days rest as one course. CDDP was administered in 24-h continuous intravenous infusion on day 8. This treatment was done every 4 weeks regularly. After 5 courses, X-ray and endoscopy examinations revealed disappearance of cancerous lesions in the stomach with an improvement in the extensibility. No cancer cell were confirmed by endoscopic biopsy, nor did a CT-scan detect carcinomatous peritonitis. The CA19-9 decreased within the normal limit. Ten months after chemotherapy was started, the patient was very healthy without a recurrence of cancer. This combined chemotherapy has administered in 8 courses, and during this period no high grade toxicities (WHO grade 3 or 4) occurred. This TS-1/CDDP chemotherapy was effective for scirrhous gastric cancer and might be administered safely even for aged patients.