Among men, cancers of the prostate, lung and bronchus, and colon and rectum account for about 50% of all newly diagnosed cancers, and prostate cancer alone accounts for about 25% of incident cases. Nuclear factor-kappaB (NF-kappaB)-activation plays a critical role in prostate cancer by NF-kappaB inhibitor kinase beta pathway-mediated inflammatory-induced tumorigenesis. A functional insertion/deletion polymorphism (-94 insertion/deletion ATTG) in the promoter of the NFKB1 gene, which encodes the p50 subunit of NF-kappaB, was identified recently. A total of 117 prostate cancer patients and 143 control subjects were recruited in this study. The NFKB1 -94 insertion/deletion ATTG genotype was determined using polymerase chain reaction-polyacrylamide gel electrophoresis. The frequency of the ATTG(2) allele in prostate cancer patients was significantly higher than that in the controls (63.7 vs. 54.5%; P=0.035, OR=1.461). Prostate cancer patients with a history of prostatitis have a 2.275 times higher risk for prostate cancer, compared to the control group (P=0.001). The functional NFKB1 promoter polymorphism is associated with increased risk of prostate cancer.