Background : A few retrospective studies showed that statin therapy prior to PCI (percutanoues coronary intervention) is associated with reduced mortality and a reduction of myonecrosis after PCI. In stable angina, ARMYDA trial has reported that atorvastatin is related with reduction of periprocedural myocardial infarction(MI). Recently, Chang SM et al. showed statin therapy prior to PCI may reduce periprocedural myonecrosis in prospective non-randomized study. And, the ARMYDA-ACS trial revealed that pretreatment with atorvastatin reduces the incidence of cardiac events in patients with acute coronary syndromes undergoing early PCI. Although statin prior to PCI has favorable effects, there have been few studies for ST elevation myocardial infarction (STEMI). Therefore, we investigate whether acute high-dose statin prior to primary PCI can have beneficial effect or not for periprocedural period and 30 days-cardiac events. Method :A total of 95 patients with STEMI were randomized to pretreatment with high dose statin (atorvastatin 80mg [n=59]) or control (10mg [n=36]). All patients were given a clopidogrel loading 600mg loading dose. All patients received long term atorvastatin treatment thereafter (10mg/day). The primary end point of this study was 30-day incidence of major adverse cardiac events (MACE : death, myocardial infarction, or target vessel revascularization). Results : All patients were attempted primary PCI. Baseline characteristics between two groups were not significantly different except hypertension (atorvastain group 61.0% vs. control group 38.9%. p=0.036). The primary end point occurred in 5.2% of patients in the atorvastatin group and in 11.4% of those in the control group (p=0.268); There was no difference in terms of MACE at 30 days. But, periprocedural MI was significantly lower in the atorvastatin group (0% vs. 11.1%, p=0.011). Conclusions : This study showed no difference in MACE at 30 days between two groups. But this study indicates that the even short-term pretreatment with atorvastatin may improve periprocedural MI in patients with STEMI undergoing primary PCI. Currently, we continue to enroll patients and waiting for final results.