Background: Human pathogens have been recognized as having a considerable possible effect on male infertility. Recent studies have shown the role of viral infections as an idiopathic pathogenesis of male infertility including cytomegalovirus. This study aimed to detect human cytomegalovirus antibody in serum among infertile male and to find out the association of this virus with seminal abnormality. Materials and Methods: Froma known ninety infertile men, serum samples were collected and tested for anti-CMV IgG and IgM using enzyme-linked immune sorbent assay (ELISA). Personal and clinical data were obtained. Comparison between anti-CMV IgG and IgM results and abnormal semen parameters were performed. Results: In this study,Anti-CMV IgM, anti- CMV IgG and both were detected in 14 (15.5%), 83 (92.2%), and in 14 (15.5%) of serum samples, respectively. This study revealed that there was significant association between anti-CMV IgG and IgM results and azoospermiea, oligozoospermia, asthenozoospermia and teratozoospermia. However, there was no significant association between demographic data and anti-CMV IgG and IgM result. Conclusion: Human cytomegalovirus was present in high percentage among infertile men and the virus had many effects on semen parameters. CMV seems to play an important role in male infertility.