Interleukin (IL)-16 plays a fundamental role in inflammatory diseases, as well as in the development and progression of tumors. Genetic variation in DNA sequence of IL16 gene may lead to altered cytokine production and/or activity, and this variation may modulate an individual's susceptibility to nasopharyngeal carcinoma (NPC). To test this hypothesis, we investigated the association of IL16 gene polymorphisms and serum IL-16 levels with NPC risk in a Chinese population. We analyzed IL16 gene rs11556218 T/G, rs4778889 T/C, and rs4072111 C/T polymorphisms using PCR-RFLP and DNA sequencing, and serum IL-16 levels were measured by ELISA. The IL16 rs11556218 T/G polymorphism was significantly associated with the susceptibility to NPC patients. The TG genotype was associated with a significantly higher risk of NPC as compared with the TT genotype (OR = 2.05, 95% CI 1.04-4.01; p = 0.037). Patients carrying the G allele had a significantly higher risk for developing NPC compared with individuals carrying the T allele (OR = 1.79, 95% CI 1.07-3.01; p = 0.027). The serum IL-16 levels were increased in NPC patients compared with controls (p < 0.01); the genotypes carrying the IL16 rs11556218 G variant allele were associated with increased serum IL-16 levels compared with the homozygous wild-type genotype in NPC patients (all p values <0.01). Our data suggested that IL16 rs11556218 T/G polymorphism was associated with increased susceptibility to NPC through increasing the production of serum IL-16 levels.