Seminal fluid was collected from all males attending a clinical laboratory for routine semen analysis, seminal fluid analysis was performed according to World Health Organization guidelines, all of the 63 infertile males were suffering from reduced sperm concentration (9.42 ± 8.70 million/ml), reduced progressive motility (2.89 ± 5.45%) and abnormal sperm morphology (27.06 ± 16.50%), while control group has higher values thus, there was a highly significant difference in semen parameters between the two groups. Whole genomic DNA was extracted from all semen samples, DNA concentration and purity were assessed using gel electrophoresis and Nanodrop techniques, DNA integrity was checked using the β-globin gene as an internal control, the targeted region was amplified by polymerase chain reaction (PCR) technique followed by the detection of PCR product (158bp). A successful amplification been has approved when the molecular size of bands linked with the targeted regions. The number of patients involved in the detection of STDs was (63), STDs detection using a specific kit by multiplex real-time PCR was included the detection of (Chlamydiatrachomatis/ Neisseriagonorrhoeae/ Mycoplasmagenitalium and Trichomonasvaginalis), and the number of patients positive for one or two bacteria was 21 of 63 (33.3%). The percentage of C.trachomatis infection was (17.4%), N.gonorrhoeae was (9.5%), M.genitalium was (9.5%) and T.vaginalis was (4.7%). There were (5) patients who showed mixed infections (7.9%). The Control group included (13) patients; their results showed only one infection with C.trachomatis. The results revealed an association between DNA methylation at SNRPN gene promoter, the presence of STDs infections, and reduced semen parameters that could lead to male infertility.