A trial of FP therapy, a novel systemic chemotherapy consisting of 5-FU and low-dose CDDP, was carried out in patients with advanced gastric cancer and the clinical effects were evaluated. Five hundred mg/body/day of 5-FU was continuously administered via the central venous catheter for 7 consecutive days and 10mg/day of CDDP was rapidly administered with 500ml saline on days 1-5. The regimen was repeated for at least 4 weeks. The FP therapy was carried out in 22 cases, including several patients who underwent FP as an adjuvant therapy; 1 CR, 2PR's 1MR and 2NC's were obtained among the 6 patients with clinically evaluable lesions, resulting in a response rate of 50%. In four cases, the FP therapy was given as a neoadjuvant therapy, and histopathological examination of the resected specimen revealed histological effects exceeding Grade 2 in all 4 cases. Bone marrow suppression was the most commonly observed side effect, but renal dysfunction and nausea were not found. FP therapy is considered an effective therapy against advanced gastric cancer, from the viewpoint of both the clinical and adverse effects, in comparison with conventional regimen consisting of 5-FU and a single and large dose of CDDP.