OBJECTIVE: To examine the relationship between the dissected lymph-node number and the prognosis in D(2) gastrectomy for gastric cancer. METHODS: From January 1996 to January 2005, 457 patients with primary gastric cancer undergone gastrectomy with different extent of lymphadenectomy in our hospital were followed-up in term of prognostic benefit. RESULTS: In lymph-node metastasis group, the 1-, 3-, 5-year survival rates were 82.4%, 49.0%, 33.4% with dissection of >20 nodes and 71.5%, 49.7%, 40.1% with dissection of 16-20 nodes. In the group without lymph-node metastasis, the 1-, 3-, 5-year survival rates were 98.2%, 92.7%, 84.7% with dissection of >20 nodes and 94.0%, 89.7%, 81.4% with dissection of 16-20 nodes. Whether or not it had lymph-node metastasis, the survival curve failed to show any significant difference with regard to the extent of lymph node dissection. CONCLUSIONS: As to lymphadenectomy for gastric cancer, it is enough to excise the lymph node between 16 and 20. The number of excised lymph node should not be overemphasized unless it is metastasized.