Since the introduction of TS-1 for clinical treatment of the progression or recurrence of stomach cancer, the effectiveness of combination therapy incorporating other agents with CDDP has been reported. Low-dose CDDP/TS-1 combination treatment was carried out in a case of Stage IV progressive stomach cancer showing multiple liver metastases and spleen metastasis. Regression of the primary carcinoma and reduction in size of liver metastases and spleen metastasis were observed. Grade 2 leukocyte decrease and grade 1 stomatitis were noted as adverse reactions to the treatment. Low-dose CDDP/TS-1 combination therapy was useful in this case of advanced gastric cancer.