Background: The purpose of this study is to evaluate the effect of left ventricular ejection fraction (LVEF) on clinical outcomes in patients (pts) with acute myocardial infarction (AMI) including ST-segment elevated and non-ST-segment elevated, STEMI and NSTEMI). Methods: A total of 464 patients(pts) with AMI undergoing primary percutaneous coronary intervention between 2004 to 2009 were enrolled. They were divided into two group; LVEF���40% (n=279) and LVEF<40% (n=185). The clinical follow-up end-point was total major adverse cardiac event (MACE) including death, AMI, TVR, Non-TVR Results: There were no significant differences between the 2 groups, including age, diabetes mellitus, hypertension, smoking history, hyperlipidemia, cardiogenic shock, cilostazole/beta-blocker/statin use, hemoglobin, and coronary artery disease count, except gender, STEMI, chronic kidney disease (CKD). At 2-year (follow-up, 89.2%), major clinical outcomes including myocardial infarction, target vessel revascularization (TVR), target lesion revascularization (TLR) was similar to two groups except total MACE cardiac death. However, when in-hospital mortality was excluded, total MACE and cardiac death were also similar to two groups (table, figure). Conclusions: LVEF is associated with in-hospital cardiac death and total MACE. However, LVEF doesn���t seem to be independent predictor for a major clinical outcomes except in-hospital period.