Background: Oxidative stress is one of the important causes of type 1 diabetes which can induce changes in male reproductive system. Ghrelin is a peptide hormone that has been shown to have antioxidant properties. Objective: Evaluation of  the ghrelin on testicular dysfunction of rat model of type1 diabetes mellitus induced by streptozotocin (STZ). Material and Methods: Forty adult male albino rats were divided into four equal groups: Group 1: served as normal control group received normal saline, group 2: Ghrelin –treated normal group, group 3: STZ-diabetic group, group 4: Ghrelin-treated diabetic group. At the end of experiment, rats were weighed and serum levels of blood glucose, insulin, luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone were determined. Also, epididymal sperm count and motility, testicular activity of superoxide dismutase (SOD), catalase (CAT) glutathione peroxidase (GPx), malondialdehyde (MDA), testicular weight and testicular histopathology were determined. Results: STZ-diabetic rats showed significant decrease in body weight, testicular weight, serum insulin, LH, FSH, testosterone, testicular activity of SOD, CAT, GPx, epididymal sperm count and motility, and significant increase in serum glucose level and testicular MDA level associated with impairment  of testicular histoarchitecture as compared to control group. Ghrelin  administration into diabetic rats resulted in significant increase in the body weight, testicular weight, serum insulin, LH, FSH, testosterone, testicular activity of SOD, CAT, GPx, epididymal sperm count and motility, and significant decrease in serum glucose, and testicular MDA levels associated with restoration of testicular histoarchitecture nearly to normal as compared to diabetic group. In the  normal group, ghrelin resulted in significant increase in body weight, testicular weight,  testicular activities of SOD, CAT, and GPx, sperm motility and significant decrease in testicular MDA, while it produced insignificant changes in the serum levels of glucose, insulin, FSH, LH, testosterone, and sperm count. Conclusion: Ghrelin has a protective effect against testicular dysfunction in STZ-induced diabetic rats which may be due to its antioxidant properties and improvement of insulin and glucose levels.