A 67-year-old male with advanced gastric cancer and lymph node metastasis as well as a tumor embolus in the portal vein was treated by S-1/cisplatin therapy. The serum alpha-fetoprotein levels were elevated to 836 ng/ml at the first visit. After one course of chemotherapy, the patient showed stable disease; the serum level of alpha-fetoprotein also decreased to 626 ng/ml after a transient increase, and therefore reduction surgery was performed. A total gastrectomy with a distal pancreatectomy, splenectomy, and regional lymph node dissection was performed. The resected specimen was diagnosed to be alpha-fetoprotein-producing gastric cancer. There were no metastatic foci in the resected lymph nodes, presumably due to the preoperative chemotherapy. S-1/cisplatin therapy was continued after the operation to treat the remaining tumor embolus in the portal vein. After one course of this therapy, the tumor embolus disappeared. However, a lymph node measuring 1.5 cm in diameter appeared in the hepatoduodenal ligament. Therefore, the chemotherapy was changed to paclitaxel monotherapy. After 2 courses of paclitaxel monotherapy, the lymph node swelled, and thus 5'-deoxy-5-fluorouridine was added to the paclitaxel regimen. After 5 courses of this regimen, the lymph node swelling disappeared without any other new lesions and a total of 21 courses were performed. The patient remained stable for over 8 years without recurrence. The expression of chemoresistance-related proteins was retrospectively analyzed by immunohistochemistry to evaluate the chemoresistance. The ortate phosphoribosyltransferase expression was strongly positive, and the good outcome in this case may have been associated with this result.