Background:Methamphetamine (MA) was shown to have harmful effects on male reproductive system. Objective:To investigate probable effects of daily administration of MA on sperm parameters and chromatin/DNA integrity in mouse.Material and Methods:Thirty-five NMRI male mice were divided into five groups including low, medium, and high dosage groups which were injected intraperitoneally with 4, 8 and 15 mg/kg/day for 35 days, respectively. Normal saline was injected in sham group and no medications were used in control group. Then, the mice were killed and caudal epididymis of each animal was cut and placed in Ham’s F10 medium for sperm retrieval. To evaluate sperm chromatin abnormalities, the aniline blue, toluidine blue and chromomycine A3 were used. For sperm DNA integrity and apoptosis, the acridine orange, sperm chromatin dispersion, and TUNEL assay were applied. For sperm morphology, Papanicolaou staining was done Results:Normal morphology and progressive motility of spermatozoa decreased in medium and high dosage groups in comparison with the control group (p=0.035). There was a significant increase in rate of aniline blue, toluidine blue, and chromomycine A3 positive spermatozoa in high dosage group. In a similar manner, there was an increase in rates of acridine orange, TUNEL and sperm chromatin dispersion positive sperm cells in high dosage group with respect to others.Conclusion:MA abuse in a dose-dependent manner could have detrimental effects on male reproductive indices including sperm parameters and sperm chromatin/DNA integrity in mice.