Backgrounds: It has not been described well how reperfusion therapy (RT) was conducted in acute myocardial infarction (AMI) according to age. The aim of this study was to evaluate the pattern of RT for acute ST elevated MI in different age group. Methods: As part of KAMIR study, 3871 AMI patient admitted to hospital within 12 hours of symptom onset were enrolled in this study. The age was arbitrary divided into 3 groups as follow; Group I: age���50 (n=719), Group II: 51���age���75 (n=2415), Group III: age���76 (n=737). Initial strategy of RT including primary percutaneous coronary intervention (PCI), thrombolytic therapy (ThT), facilitated PCI and conservative therapy was analyzed among groups. Results: Any RT was performed less frequently in elderly patients than young age group (Group I, 90%; Group II, 87%; Group III, 79%, p<0.001). Primary PCI was the most common RT at any ages (p<0.001) but, reperfusion modality was similar in different groups. In patients who underwent PCI, the rate of stent use had no differences (range: 94.1-94.6%, p=0.932). Pre-TIMI grade 3 flow after thrombolysis was restored with similar proportion among each groups (range: 50.9-60.9%, p=0.502). Time-intervals from symptom onset to door, needle or 1st balloon were significantly shorter in younger patients. However, success and hospital death rate according to the strategy of RT were not different among each groups (p=0.189). At 6th month, cardiac death was less frequently developed in patient with any RT (p=0.021). Multivariate analysis revealed that RT use was 19% lower at group II and 47% lower at group III (p=0.030). Conclusion: This study showed that RT was underused in elderly patients and patients who were not treated RT showed higher rate of cardiac death at 6th month.