Nasopharyngeal carcinoma (NPC) is a common malignancy in southern China and Southeast Asia. Nuclear factor-kappaB (NF-kappaB)-activation plays critical roles in Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) mediated tumorigenesis in NPC. A functional insertion/deletion polymorphism (-94 insertion/deletion ATTG) in the promoter of NFKB1 gene, which encodes the p50 subunit of NF-kappaB protein complex, was recently identified. This study found that the frequency of ATTG(2) allele in NPC patients was significantly higher than that in control subjects (66% vs. 57.1%, p=0.015, OR=1.453), suggesting that the functional NFKB1 promoter polymorphism is associated with increased risk for NPC.