Background Aspiration thrombectomy(AT) in patients undergoing percutaneous coronary intervention (PCI) for patients with acute myocardial infarction(AMI) has not demonstrated effective in randomized trials. However,in patients with high-risk angiographic characteristics, AT may be an effective method. Method From May 2002 to June 2008, 166 patients (116 males, mean age of 60.75짹11.82 years) were retrospectively analyzed. All patients underwent primary PCI for AMI with Thrombolysis In Myocardial Infarction (TIMI) 0 to 1 flow or visible thrombus. 35 patients underwent primary PCI with AT and 131 patients underwent primary PCI without AT (non-AT). TIMI flow rate after intervention, major adverse cardiac events (mortality, reinfarction, revascularization) at 1 year clinical follow up were compared. Result Baseline characteristics were similar between two groups. TIMI flow rate after intervention were investigated; in total patients, TIMI 3 flow was 81.9 %, TIMI 2 flow was 11.4 %, TIMI 0-1 flow was 6.6%; The AT group more frequently achieved TIMI 3 flow after the intervention (97.1% AT vs 77.9% non-AT; p=0.047). AT reduced major adverse cardiac events at at 1 year clinical follow up (2.9% AT vs 22.6% non-AT; p = 0.008) and didn't siginificantly reduced mortality (0% AT vs 7.6% non-AT; p = 0.09). conclusion In patients undergoing primary PCI for AMI with TIMI 0 or 1 flow or visible thrombus, AT was associated with increased TIMI 3 flow rates and decreased major adverse cardiac events.