AIMS: The prostate cancer gene 3 (PCA3) is a prostate-specific, non-protein-coding RNA. It is overexpressed in prostate cancer compared with the normal prostate and has a negative expression in other tissues. This case-control study sought to analyze the frequency of the polymorphism PCA3 -845 G>A in participants without prostate cancer and patients with metastatic prostate cancer. RESULTS: Carriers of GA and AA genotype had a higher risk for metastatic prostate cancer (odds ratio [OR] for genotype GA, 1.79 [95% confidence interval (CI), 1.14-2.29]; p=0.007; OR for genotype AA, 2.38 [95% CI, 1.22-4.65]; p=0.006). Furthermore, the recessive model showed that A allele carriers have an increased risk for developing metastatic prostate cancer (OR, 1.91 [95% CI, 1.26-2.90]; p=0.001). CONCLUSIONS: These results suggest a link between PCA3 and metastatic prostate cancer. The evaluation of individual genetic profiles, according to the PCA3 -845 G>A polymorphism, may elucidate the function of this gene and the mechanisms involved in its regulation and role in prostate cancer.