AbstractThe results of adjuvant chemotherapy trials in gastric cancer are less favorable in European and Anglo‐American countries than in Japan. The majority of findings in Western countries leads to the conclusion that the routine application of adjuvant chemotherapy for gastric cancer cannot be recommended. The therapeutic benefit reported in Japanese studies is possibly due to the fact that chemotherapy is started intraoperatively or during the immediate postoperative period in Japan as opposed to the procedure in the majority of Western countries. The effectiveness of adjuvant chemotherapy may be improved by intraperitoneal drug administration because peritoneal seedings and lymph node metastases are the major cause of treatment failure after curative gastric cancer surgery. Since the efficacy of adjuvant chemotherapy is influenced by the responsiveness of cancer cells to cytotoxic agents, preoperative chemotherapy could improve the selection of patients for subsequent postoperative adjuvant treatment trials in the future.