S-1/CDDP combination chemotherapy is conducted in many institutions, but most patients are hospitalized at the time of CDDP administration. We performed S-1/CDDP combination chemotherapy in 15 patients with advanced gastric cancer, and CDDP was administered in the outpatient department for 8 outpatients out of the 15 patients without renal failure or dysfunction. If outpatient chemotherapy can safely perform a regimen based on evidence, it brings about improvement in the QOL of the patient, and there are considerable advantages for economical care delivery. S-1/CDDP combination chemotherapy for outpatients was regarded as feasible with appropriate patient guidance.