Introduction: LDL Cholesterol/HDL Cholesterol (LDL-C/HDL-C) ratio and triglyceride/HDL Cholesterol (TG/HDL-C) ratio have been increasingly recognized as stronger prognostic factors of coronary artery disease than individual level of LDL-C and HDL-C. However, the significance of non-HDL cholesterol/HDL cholesterol (non-HDL-C/HDL-C) ratio, as another cardiovascular risk predictor, has not been investigated in patients who undergo percutaneous coronary intervention (PCI). Hypothesis: Higher non-HDL-C/HDL-C ratio has a strong correlation with poor long-term clinical outcome in patients on statin within target LDL cholesterol level after PCI with drug eluting stents (DES). Methods: A total of 9,292 consecutive patients who underwent PCI with DES from January 2004 to December 2009 were enrolled. Among these, we analyzed 2,704 patients with follow up lipid panel who had been kept on statin and attained low LDL-C (LDL-C < 100 mg/dL). We defined a major adverse cardiac event (MACE) as the composite of all-cause death, nonfatal myocardial infarction, and revascularization of any cause. Results: The median follow up period was 28.2 months. Multivariate Cox proportional hazards regression analysis indicated that the presence of multivessel disease, angiographic ACC/AHA B2C lesion, non-LDL-C/HDL-C ratio were significantly associated with increased incidence of MACE after adjusting multiple variables(adjusted HR =1.470, 1.248, 1.433, respectively). Conclusions: Non-HDL-C/HDL-C ratio can be a potential risk predictor in patients on statin with target LDL-C in the drug eluting stent era. Key words: Non-HDL Cholesterol, HDL Cholesterol, statin, percutaneous coronary Intervention, drug eluting stents