We prospectively analyzed the adverse effects and outcomes of 15 patients with stage IV gastric cancer who underwent palliative gastrectomy from December, 2002 to May, 2008 and subsequently received combination therapy of S-1 and 4-h infusion of cisplatin. The National Cancer Institute common toxicity criteria (version 3. 0) were applied to evaluate the adverse effects of this therapy, and the Kaplan-Meier method was used to plot the survival curve. The side effects most frequently observed were anorexia (grade 3; 33%), although one case of grade 4 who was easily fatigued was noted during the first course and could not receive further courses of this therapy. The 2-year survival rate was 33% and median survival time was 31 months. It has been suggested that 24-h infusion of cisplatin combined with oral S-1 after reduction surgery might improve survival in patients with stage IV gastric cancer.