The fact that intron single nucleotide polymorphisms could regulate gene expression or even alter gene expression levels has been the focus of attention. To study the relationship between the intron 11 C/A single nucleotide polymorphism of XPC gene and the efficacy of vinorelbine and cisplatin (NP) chemotherapy, 164 patients with non-small cell lung cancer (NSCLC) taking NP chemotherapy drugs were evaluated according to the efficacy of the treatment. We used polymerase chain reaction restriction fragment length polymorphism to examine the C/A polymorphism in the XPC gene intron 11 of the DNA samples extracted from peripheral blood. It was found that the frequency of patients in the effective group with C/C+C/A genotype (37.6%) had significant difference to chemotherapy than that of patients with A/A homozygotes (27.7%) in the same group (P=0.043, odds ratio=2.366, 95% confidence interval=1.026-5.457). Therefore, NSCLC patients with the C/C+C/A genotype are more sensitive to NP treatment than those with the A/A genotype. The XPC gene intron 11 C/A polymorphism may be a predictive biomarker for sensitivity to NP chemotherapy in patients with NSCLC.