Many studies have indicated that lymph node metastases and the depth of invasion of the primary tumor are the most reliable prognostic factors for patients with radically resected gastric cancer. Recently the ratio between metastatic and examined lymph nodes (n ratio) has been proposed as a new prognostic indicator. The aim of this study was to evaluate the prognostic value of n ratio in patients with gastric cancer.We retrospectively reviewed the data of 399 patients who had undergone radical resection for gastric carcinoma.N ratio was significantly greater in patients with large and undifferentiated tumors. Moreover, it was significantly related to both the number and location of lymph node metastases. Survival curves showed that n ratio was strictly related to patients' survival. Multivariate analysis confirmed that it was an important independent prognostic indicator.N ratio is useful to better evaluate the status of lymph node metastases in patients with gastric cancer submitted to radical surgery. Moreover it is a very important independent prognostic factor for gastric cancer.