The Toll-like receptor 4 (TLR4) has a wide spectrum of bacteria recognition receptors that may be involved in the signaling of the immune responses in the prostate. A few association studies have assessed the relationship between the risk of prostate cancer (PC) and the polymorphism in the TLR4 gene in European-ancestry populations. To evaluate the association of TLR4 polymorphisms and the risk for PC in Korean men, we genotyped five single-nucleotide polymorphisms (SNPs) of the TRL4 gene (rs11536858, rs1927914, 1927911, rs11536891, and rs11536897) by PCR-restriction fragment length polymorphism from unrelated 157 PC patients and 143 age-matched controls. The rs1927911 SNP increased the risk of PC (adjusted odds ratio ORadj=2.73, 95% CI=1.54-4.87 for the TC genotype; ORadj=6.68, 95% CI=3.27-13.66 for the CC genotype). The GG genotype of the rs11536858 SNP also carried increased risk (ORadj=2.296, 95% CI=1.07-4.93). There was no statistically significant correlation between any of the SNPs of TRL4 and such PC prognostic factors as Gleason grade, initial prostate-specific antigen level, or tumor stage. In conclusion, inherited differences in the TLR4 gene influence the risk of PC in Korean men.