Background: Although curative resection is the treatment of choice for gastric cancer, controversy exists about the adequate extent of lymph node dissection when resection is performed. Methods: We retrospectively assessed 85 patients who underwent a limited lymphadenectomy (D1) and 71 who had an extended lymph node dissection (D2) in a single institution between 1990 and 1998 (median follow-up, 37.3 months). Prognostic factors were assessed by Cox proportional hazard models adjusted for potential confounders. Results: We found no significant difference in the length of hospital stay (median, 12.1 and 13.1 days), overall morbidity (48.2% and 53.5%), or operative mortality (2.3% and 0%) between D1 and D2, respectively. Five-year survival in the D2 group was longer (50.6%) than in the D1 group (41.4%) for tumor stages (tumor-node-metastasis) >I. In multivariate analysis, tumor-node-metastasis stage (hazard ratio for stages >I vs. 0-I, 11.6), the ratio between invaded and removed lymph nodes, the presence of distant metastases, Laurén classification, and the extent of lymphadenectomy (hazard ratio for D1 vs. D2, 2.3; 95% confidence interval, 1.25-4.30) were the only significant prognostic factors. Conclusions: Our experience shows that extended (D2) lymph node dissection improves survival in patients with resected gastric cancer.