['The aims of this study were to investigate the effects of atorvastatin pretreatment on the oxygen free radicals and its protective role on the myocardial cell during the ischemic reperfusion injury.', 'One hundred fifty-six patients with ST elevation myocardial infarction undergoing percutaneous coronary interventions, aged from 29 to 85 years, were selected. Eighty patients were randomly assigned to placebo group and 76 to statin treatment (80-mg loading dose given a mean of 1.5 hours before percutaneous coronary intervention). The nitrogen monoxidum, malondialdehyde, and superoxide dismutase (SOD) were assayed before and after reperfusion. Thrombolysis in myocardial infarction (TIMI) grade and corrected TIMI frame count were measured after reperfusion. The creatine kinase-MB and troponin T peak levels after myocardial infarction were recorded.', 'There was no significant difference in the nitrogen monoxidum, malondialdehyde, and SOD levels (P > 0.05) between the 2 groups before intervention. After the reperfusion, significantly lower creatine kinase-MB (289.9 ± 180.8 U/L vs. 360.5 ± 206.4 U/L, P = 0.025) and troponin T (4.60 ± 3.13 ng/mL vs. 6.01 ± 4.98 ng/mL, P = 0.035) peak levels can be observed in the statin versus the placebo group, and the SOD level of the statin group is higher than that of the placebo group (34.14 ± 15.07 U/mL vs. 29.06 ± 12.76 U/mL, P = 0.024).'] Is protection by atorvastatin pretreatment in patients undergoing primary percutaneous coronary intervention associated with the lower levels of oxygen free radicals?