Introduction: Weakening of the liver antioxidant capacity and oxidative damage play a crucial role in the genesis of hepatocellular damage during diabetic states. Considering to the antioxidant property of rosuvastatin, the aim of present study was to investigate whether rosuvastatin improves antioxidant capacity and oxidative damage of liver tissue in diabetes. Materials and Methods: Twenty-four rats were randomly divided into four groups (n=6 each), normal, treated normal, diabetic and treated diabetic groups. Diabetes was induced in rats by an intravenous injection of streptozotocin (40 mg/kg). Treated rats received rosuvastatin (10 mg/kg) daily by a gavage tube for sixty days. At the end, blood samples were collected for measuring blood glucose, and liver tissue was removed to determine malondialdehyde, glutathione and NOx (nitrate and nitrite) contents as well as catalase and superoxide dismutase activities. Results: Induction of diabetes (blood glucose >300 mg/dL) significantly increased the malondialdehyde content (4.00±0.44 µMol/L), compared with the normal group (1.08±0.39 µMol/L), whereas rosuvastatin significantly decreased it (2.42±0.56 µMol/L), without changing blood glucose levels. Diabetes decreased the activities of catalase and superoxide dismutase by 81 and 54%, respectively. Treatment with rosuvastatin increased the catalase activity (90%) and glutathione content (65%) in diabetic rats. Also, diabetes significantly decreased the NOx content (15±1 µMol/L), compared to the normal group (34±15 µMol/L), whereas rosuvastatin significantly increased it (61±16 µMol/L). Conclusion: Our results indicate that rosuvastatin can increase the antioxidant capacity of diabetic liver, and treatment with rosuvastatin may hence improve the tissue and oxidative damages of the liver during diabetic states.