Background Evidence suggests that there is a link between diabetes mellitus and Vitamin A. Moreover, it has been reported that diabetes induces oxidative stress. Lately, a wide attention has been developed to the protective biochemical function of natural antioxidants contained vitamins, which can reduce the oxidative damage caused by free radical species. Objective To investigate the anti-obesity, anti-diabetic and anti-oxidative effects of vitamin A in streptozotocin (STZ)-induced diabetic mice. Methods Male mice were randomly divided into three groups: Control- nondiabetic, received a normal diet and water; Control-diabetic, received STZ 45mg/kg once intraperitoneally; and Treated-diabetic, received both STZ as before plus Vitamin A (4-IU/day) orally daily for 16 weeks. Food intake, body weight, fat mass, fasting blood glucose, serum insulin, and lipid profile were estimated. Also, superoxide dismutase (SOD), glutathione peroxidase (GPO), catalase (CAT), and malonaldehyde (MDA) were measured. Results Treated diabetic mice with Vitamin A showed a significant improvement in their body weight, fat mass, lipid profile as well as SOD, GPO and CAT compared to Control-diabetic mice. However, Vitamin A caused no significant change on fasting blood glucose and insulin levels. Furthermore, plasma level of MDA was significantly elevated in diabetic mice compared to normal mice. Diabetic mice treated with vitamin A had a significantly reduced level of MDA, suggesting that vitamin A might have a vital role in the protection of tissues from damage by free radicals. Conclusion Supplementation with vitamin A may be a useful treatment strategy for diabetic patients to reduce/prevent the pathological complications of diabetes.