Methylenetetrahydrofolate reductase (MTHFR) has a critical role in spermatogenesis process and altered expression level of this gene may leads to male infertility. In the present study, the assocaitions of gene expression and promoter methylation of MTHFR with risk of oligozoospermia was assessed. Sperm DNA and RNA were extracted from 20 oligozoospermia men and 20 controls consisting of healthy fertile men. Following the modification of DNAs by sodium bisulfite treatment, the methylation status of the MTHFR gene promoter was quantified by methyl specific PCR. MTHFR expression evaluated by Quantitative PCR, or real-time PCR, (qPCR). Our data revealed a significant association of CpG island promoter methylation and MTHFR expression with risk of oligospermia (P = 0.031). The prevalence of methylation in promoter region of MTHFR can be a useful molecular biomarker to predict the predisposition of male infertility.