en Original Original <p><b>Introduction:</b> Infertility is a common phenomenon in modern societies. Today, use of assisted reproductive technologies (ARTs) for treatment of infertility is common, and cryopreservation is one of these technologies. Cryopreservation has impact on the function and percentage of fertility of human sperm. In this study, motility, viability, nitric oxide, and DNA apoptosis were assessed before and after cryopreservation process of human semen samples in normozoospermic men. </p> <div><b>Methods:</b> We divided 20 semen samples of normozoospermic men into 2 groups: fresh group as a control and frozen–thawed group. Each semen sample has been aliquoted to 4 parts in cryotube for assessment of viability by eosin and negrosin staining, motility by invert microscope, nitric oxide and DNA apoptosis content by flow cytometry. </div> <div><b>Results:</b> Normozoospermic men frozen–thawed semen samples showed significant (p<0.05) difference in viability, motility, nitric oxide and DNA apoptosis compared with fresh semen samples. </div> <div><b>Conclusion:</b> cryopreservation process has impact on viability, motility, intracellular nitric oxide and DNA apoptosis content in fertile human semen samples.</div> Viability, Nitric Oxide, DNA Apoptosis, Cryopreservation, Spermatozoa 17 23 http://anatomyjournal.ir/browse.php?a_code=A-10-25-26&slc_lang=en&sid=1 Sara Saeednia 1003194753284600992 1003194753284600992 No Dept, Anatomy, Baqiyatallah University of Medical Sciences, Tehran, Iran. Hossein Bahadoran 1003194753284600993 1003194753284600993 Yes Dept, Anatomy, Baqiyatallah University of Medical Sciences, Tehran, Iran. Fardin Amidi 1003194753284600994 1003194753284600994 No Dept, Anatomy, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Hossein Asadi 1003194753284600995 1003194753284600995 No Dept, Anatomy, Baqiyatallah University of Medical Sciences, Tehran, Iran.