The Japanese gastric cancer clinical practice guideline recommends FOLFOX as one of the first-line chemotherapy for advanced gastric cancer. Since FOLFOX is administered intravenously, it is helpful for patients who have difficulty in oral intake. Herein, we report a patient in which FOLFOX was significantly effective after failure to treatment with S-1 plus CDDP. A 75-year-old gastric cancer patient with paraaortic lymph node metastasis and multiple liver metastases(Stage ⅣB)was treated. Severe stomatitis and impaired consciousness due to dehydration appeared after administration of S-1 plus CDDP. After his general condition recovered, we changed his regimen to FOLFOX. No serious adverse events were observed, and partial response was achieved after 4 courses of treatment. Partial response was maintained until the onset of oxaliplatin drug allergy in the 10th course. FOLFOX is a promising option for patients with difficulties in oral intake.