mellitus (DM), primary or idiopathic is a chronic disorder of the carbohydrate, lipid and protein metabolism. DM may impact male reproductivefunction at several levels. It is shown that DM has detrimental effects on sperm parameters in human and experimental animals.Objective: The aim of this study was to observe the effects of diabetes on sperm parameters (viability, count, morphology and motility) and evaluation of spermchromatin quality in mice. Materials and Methods: Totally twenty adult male Syrian mice were divided randomly into 2 groups (n=10). The animals of group A were considered as controlswhile group B mice were diabetic that received a single dose (200 mg/kg)streptozotocin (STZ) intra peritoneally. After 35 days, the cauda epididymis of each diabetic mouse was dissected and placed in culture medium for 30 min. The swimoutspermatozoa were analyzed for count, motility, morphology and viability. The sperm chromatin quality and DNA integrity, was evaluated with Aniline Blue (AB),Toluidine blue (TB), Acridine orange (AO) and Chromomycin A3 (CMA3) staining. Results: In sperm analysis, the diabetic mice had poor parameters in comparisonwith control animals (p=0.000). Regarding sperm chromatin quality, the results of TB and AO tests showed statically significant differences between two groups, but in AB and CMA3 staining, we didn’t see any differences between them. Conclusion: The results showed that STZ-induced diabetes mellitus may influence the male fertility potential via affecting sperm parameters and DNA integrity inmice. However, according to our data, the diabetes doesn’t have any detrimental effects on histone-protamines replacement during the testicular phase of sperm chromatin packaging.