Objective: A retrospective study was performed to analyze the impact of vascular invasion on prognosis in a series of radically resected non-small cell lung cancer (NSCLC) and the subgroup of T1-4 nodal negative NSCLC patients. Methods: A total of 259 NSCLC patients who had undergone radical resection were entered into this study. Detailed clinical data including five-year survival were obtained for all the patients. The tumors were reviewed for the presence or absence of vascular invasion. Fisher's exact tests were used to assess the relationship between vascular invasion and other clinicopathological variables. Survival time was defined as the interval from the date of operation to either death from lung cancer or the last follow-up. Univariate analysis of survival curve was performed by the Kaplan-Meier method using the Log rank test. Multivariate survival analysis was carried out by Cox regression. P〈0.05 was considered statistically significant. Results: In 259 patients, 33 cases were diagnosed as having vascular invasion. The overall 5-year survival was 37.5%. Patients with vascular invasion had a median survival of 20 months compared with 43 months for those without vascular invasion (P〈0.01). Multivariate analysis indicated that vascular invasion was a significant independent prognostic predictor for shortened cancer-related survival in the patients. The relative risk for cancer-related survival was 2.2-fold greater in patients with vascular invasion (95% CI: 1.45-3.32). Subgroup analysis revealed that patients with vascular invasion had a 5-year survival of 11.1% compared with 57.1% for those without vascular invasion in the resected lung cancer patients at T1-4N0M0 (P=0.002). Conclusion: Vascular invasion can serve as an independent prognostic factor in radically resected NSCLC.