Backgrounds: The novel value of statin therapy after acute ST elevated MI (STEMI) has been well known but, clinical outcomes according to the time of administration was not elucidated. This study aimed to know how statin therapy in hospitalization and after discharge effects on early outcomes after acute STEMI, especially, in the patient underwent percutaneous coronary intervention (PCI). Methods: As part of KORMI study, this study enrolled 3584 STEMI patients (mean age: 63 짹 13, male: n=2684, 74.9%) underwent PCI, from January 2008 to June 2009. Patients were stratified into 4 groups as follow; Group I: Statin therapy both in hospitalization and after discharge (n=2653, 74%), Group II: only in hospitalization (n=309, 8.6%), Group III: only after discharge (n=157, 4.4%), Group IV: no statin therapy (n=465, 13%). Major adverse cardiovascular events (MACE) including death, recurrent MI, and revascularization rate were analyzed and compared among each groups. Mean follow up duration was 234 짹 113 days. Results: On multivariate logistic regression analysis, the use of statin during hospitalization appeared to be influenced by several factors including statin use before STEMI attack, multiple diseased vessels, lesion type, TIMI flow III after PCI, stent diameter, low density lipoprotein cholesterol, serum C-reactive protein level. At 6th month on follow up, the higher rate of MACE was observed in Group III and Group IV (2.3%, 3.9%, 5.1%, and 4.9% from group I to Group IV, respectively, p=0.004) (Figure 1). After adjusting for other factors, Cox-proportional hazard analysis revealed that all 3 groups had significantly increased risk of total MACE as compared with group I [(Group II: hazard ratio (HR) 3.20 (95% confidence interval (CI) 1.31 to 7.86, p=0.011), Group III: HR 3.84 (95% CI 1.47 to 10.02 p=0.006), Group IV: HR 3.17 (95% CI 1.59 to 6.40, p=0.001)]. Conclusion: This study showed that the impacts of early and continuous statin medication on early outcomes in STEMI patients who underwent PCI.