Background Statins have been known to possess antioxidant properties as well as their cholesterol-lowering effect. However, recent studies have suggested that statin reduced antioxidant vitamins such as vitamin E and coenzyme Q10 attributed, in part, by lipid lowering, which results to cause impairment of left ventricular function unintentionally. We investigated the effects of simvastatin on the blood lipids, LDL oxidation and plasma antioxidant status and whether these effects were associated with the changes in plasma lipid soluble vitamin levels. Methods Simvastatin (20-40 mg/day) was administered for 8 weeks in seventy-six hypercholesterolemic patients (mean age 59 yrs, 25 males and 51 females). We measured plasma lipids, oxidized LDL (ELISA), TRAP (total radical trapping antioxidant potential, photometric method) and lipid soluble vitamins (RP-HPLC) at baseline and 8 weeks of adiministration. Results Simvastatin significantly lowered serum levels of total cholesterol and LDL-cholesterol by 30.1 % and 41.9 %, respectively. A significant reduction in oxidized LDL levels (p<0.0001) and improvement in plasma antioxidant status as measured by TRAP (p<0.05) after 8 week simvastatin treatment were observed. With regard to the effect of simvastatin on plasma antioxidant vitamin levels, there were significant increases in the levels of lipid-corrected retinol (46.6%, p<0.0005), alpha-tocopherol (75.3%, p<0.0001) and gamma-tocopherol (94%, p<0.0005) after 8 week simvastatin treatment. Lipid-corrected levels of coenzyme Q10 and carotenoids remained unchanged after simvastatin treatment. Significant positive relation was noted between the changes in the TRAP and the changes in gamma-tocopherol levels (r=0.315, p<0.005). Conclusion Our results showed that simvastatin reduced blood lipids, circulating oxidized LDL and improved plasma antioxidant status without altering antioxidant vitamin system. These data indicate that simvastatin not only decreases oxidants but also restores antioxidants, therefore, synergizes biological effects of antioxidants.