It is evident that genetic factors play critical roles in prostate cancer development. GWAS (genome-wide association studies) in multiple ethnic groups have been identifying more than 100 loci or genes which was significantly associated with prostate cancer susceptibility. They include several loci at 8q24, prostate-specific gene, inflammation gene, and metabolism-related genes. Risk prediction for prostate cancer by combining multiple SNPs is still primitive and not sufficiently accurate for clinical use, but this model could have a potential to affect clinical decision when it is applied to patients with gray-zone PSA or very high risk of prostate cancer.