A 56-year-old man presented with dysphagia, and was found to have a type 3 advanced gastric cancer with bilateral multiple lung metastases. This patient was treated with low-dose 5-FU plus CDDP chemotherapy. In the first course, CDDP (6 mg/m2/day) plus 5-FU (300 mg/m2/day) were infused for 5 successive days a week, but a tumor response was not achieved. Therefore, in the second course, CDDP (6 mg/m2/day) plus 5-FU (600 mg/m2/day) were infused every other day (3 days a week). In response to the treatment, both the gastric tumor and the lung metastases almost completely disappeared (reduction rate 95%), and PR was achieved. The CEA level markedly decreased, from 260.3 to 1.4 ng/ml and the patient's symptoms disappeared. Following this treatment, low-dose CDDP plus UFT therapy was performed and the PR was maintained for 12 months. This report shows a case of advanced gastric cancer that responded to low-dose 5-FU plus CDDP.