Single-nucleotide polymorphisms located in the microRNA biogenesis pathway could alter the risk for developing prostate cancer. The present study was intended to identify common genetic variants responsible for prostate cancer susceptibility in the GEMIN4 gene. The high-resolution melting method was used to genotype seven polymorphisms (rs7813, rs4968104, rs3744741, rs2740348, rs1062923, rs910925, and rs910924) in the GEMIN4 gene in 300 prostate cancer patients and 244 matched controls. The encouraging discovery in this study was in the rs2740348. Patients carrying the variant heterozygote GC genotype in the rs2740348 were at a 36% decreased risk of prostate cancer (odds ratio [OR] = 0.64; 95% confidence interval [CI] = 0.42, 0.99). Similarly, this variant allele carrier showed significant risk for prostate cancer (OR = 0.64). In addition, subjects carrying the homozygote TT genotype in the rs7813 had a significantly increased risk of prostate cancer (OR = 2.53, 95% CI = 1.07, 6.28). Two common haplotypes were found to be associated with decreased risk of prostate cancer. In the subgroup analysis, higher risk of more severity of prostate cancer (clinical stage III and IV) was observed in individuals with the rs7813 TT genotype (OR = 2.64, 95% CI = 1.02, 7.64), while lower risk of more severity of prostate cancer was observed in individuals with the rs3744741 T allele (OR = 0.69, 95% CI = 0.50, 0.96). Overall, our study provides substantial support for the association between the GEMIN4 gene and the risk of prostate cancer.