The patient was a 65-year-old woman with type 3 gastric cancer (por) in the upper third of the stomach invading esophagus. Because of No. 16 lymph node swelling on abdominal CT examination, she was treated with FLP (5-fluorouracil + Leucovorin + cisplatin) as a neoadjuvant chemotherapy (NAC). The activities of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) in the primary tumors upon endoscopic examination were 2.72 pmol/g tissue and 129.1 pmol/mg/min, respectively. After the second course, we carried out lower esophagectomy and spleno-total gastrectomy with D3 including the No. 16 lymph nodes. Histopathological examination of resected specimens showed dense fibrosis and xanthogranulomatous inflammation with foamy cells and giant cells. No residual carcinoma was seen (complete response). The patient is still alive with no sign of recurrence 1 year after surgery. NAC by combination of FLP is thought to be effective for the treatment of highly advanced gastric cancer, especially in cases with locally advanced disease and lymph node metastasis such as the present. Although no relations were seen between NAC effects and TS, DPD activities and TSIR in primary tumors in 12 gastric cancer patients, the survival rate of a low DPD activity group was significantly better than a high group in 106 cases undergoing adjuvant chemotherapy including 5-FU after surgery.