Purpose To investigate the expression of C-C chemokine receptor 9 (CCR9) in non-small cell lung cancer (NSCLC) and to explore its prognostic value. Methods The expression of CCR9 was detected by immunohistochemistry in tumor tissues and corre-sponding adjacent normal tissues from 119 NSCLC patients. Additionally, the correlation between CCR9 expression and the clinicopath-ologic features of NSCLC and the relationship between prognostic factors and overall survival rate were analyzed by statistical methods. Results The positive expression rate of CCR9 was significantly higher in NSCLC tissues (54. 6%) than that in adjacent normal lung tissues (10. 1%) (P<0. 05). The expression of CCR9 in NSCLC was correlated with histopathologic type, lymph node status and p-TNM stage (P<0. 05). Kaplan-Meier survival analysis suggested that the positive expression of CCR9 was negatively correlated with the overall survival rate (Log-rank=9. 917, P=0. 002). Univariate analysis showed that the lymph node status, p-TNM stage and the positive expression of CCR9 made great difference to postoperative overall survival (P<0. 05). Multivariate analysis showed that CCR9 expression was an independent prognostic factor for overall survival of NSCLC patients ( RR=0. 447, 95%CI:0. 201 ~0. 993, P<0. 05). Conclusion The expression of CCR9 may predict a poor prognosis in the patients with NSCLC, so it can be used as a novel NSCLC biomarker.