No associations were found between ESR1 XbaI (A>G) polymorphism and prostate cancer risk under any genetic models (G allele vs. A allele: OR = 1.09, 95%CI: 0.98–1.22, P = 0.118; GG + AG vs. AA: OR = 1.14, 95%CI: 0.98–1.34, P = 0.089; GG vs. AA + AG: OR = 1.08, 95%CI: 0.86–1.34, P = 0.523; GG vs. AA: OR = 1.19, 95%CI: 0.92–1.55, P = 0.174; GG vs. AG: OR = 1.03, 95%CI: 0.82–1.30, P = 0.797; respectively). The gene discussed is ESR1; the disease is Familial prostate cancer.