OBJECTIVE: To investigate the pattern of lymph node metastasis and the extent of lymph node dissection for gastric cancer. METHODS: 326 patients with gastric cancer admitted from 1990 to 1999 were analyzed retrospectively after D(2), D(3) or D(3) plus para-aortic lymphadenectomy (D(3) + PAL). RESULTS: The total incidence of lymph node metastasis was 69.9%; node involvement was 15.4% and 77.4% respectively for early gastric cancer and advanced gastric cancer. Depth of invasion, tumor size and histology affected lymph node metastasis significantly (P < 0.05). For T(1) patients, node involvement was mainly confined to N(1) and one patient had N(2) metastasis; 8.1% of T(2) patients and 28.7% of T(3), T(4) patients had N(3), M(1) lymph node metastasis. Among 107 patients who received D(3) + PAL, 16a2b1 lymph node metastasis was found in 15.0%. The patients who had 16a2b1 node involvement were all suffered from advanced gastric cancer and N(1)-N(2) node metastasis. In the patients with serosal invasion-positive tumors or tumors size over 5 cm, the incidence of 16a2b1 metastasis was high, and that of entire stomach cancer was up to 38.5%. The 3-year and 5-year survival rates for D(3) + PAL group were 60.7% and 50.0% respectively. After D(3) + PAL, the 1-and 2-year survival rate, of patients with 16a2b1 metastasis were 60.0%, 50.0% respectively. CONCLUSIONS: D(2) lymphadenectomy should be taken for patients with early gastric cancer and D(3) lymphadenectomy for those with relatively early' advanced gastric cancer. For advanced gastric cancer with suspect or confirmed N(1)-N(2) node metastasis, tumor size over 5 cm and/or serosa invasion, D(3) plus para-aortic lymphadenectomy appears to be a necessary surgical procedure.