Background: Low plasma level of high-density lipoprotein cholesterol (HDL) is known to be a risk factor of coronary artery disease. We evaluated the impact of low HDL on the angiographic and clinical outcomes in aute myocardial infarction (AMI) patients (pts) undergoing primary percutaneous coronary intervention (PCI).Methods: A total of 799 AMI pts who underwent primary PCI between January 2004 and April 2009 were enrolled. The pts were divided into two groups: Low HDL group (HDL-C<40mg/dl in male and HDL-C < 50mg/dl in female, n= 408) and control group(n=391).Results: Baseline characteristics were similar between two groups except Low HDL group had more old age, female, diabetes, triglyceride, and less cholesterol than control group. Six-month angiographic outcomes were similar between the two groups. However, Low HDL group had higher incidence ofin-hospital outcomes including total death and cardiac death than those of control group. Further, Low HDL group showed higher cumulative incidence of total death, cardiac death and target lesion revascularization major adverse cardiac events (TLR-MACEs) up to 2 years than those of control group (Table 1). Multivariate analysis showed Low HDL was an independent predictor of cardiac death up to 2 years (Adjusted OR 2.107, CI 1.01-4.39,p=0.047).Conclusions: Low HDL level was associated with higher incidence of short term and long term adverse clinical events. Particularly, Low HDL level was an independent predictor of cardiac death at 2 years. Thus, if the AMI patients undergoing primary PCI with DES with concomitant low HDL, more intensive medical therapy and careful clinical follow up would be required.