Introduction: Previous studies have shown that atorvastatin inhibits oxidative stress in different tissues of body during certain pathological conditions. The aim of this study was to examine the effects of atorvastatin treatment as an antioxidant to prevent pancreatic oxidative stress in streptozotocin-induced diabetic rats. Materials and Method: The experiment was performed in four groups of rats (n=5 each) normal, normal treated, diabetic and diabetic treated, who were made diabetic by intravenous injection of streptozotocin (40 mg/kg). After 30 days of treatment, pancreas tissue was removed under deep anesthesia. After tissue homogenization, superoxide dismutase (SOD) and catalase (CAT) activities, as well as glutathione (GSH) and malondialdehyde (MDA) levels were determined by biochemical methods. Results: In addition to increased blood glucose levels in diabetic rats (78%), enzymes activities of SOD and CAT were significantly increased, compared to the normal rats. Also, induction of diabetes significantly decreased the GSH content of pancreas by 40%, and increased MDA level by 53%. Finally treatment with atorvastatin significantly increased the content of GSH and prevented augmentation of SOD activity. Conclusion: Based on findings of this study, diabetic-induced hyperglycemia provokes the production of pancreas free radicals that lead to oxidative stress. Also, treatment with atorvastatin may prevent hyperglycemia-induced oxidative stress in the pancreas tissue of these animals.