BACKGROUND and OBJECTIVES Acute myocardial infarction in young patients is a very special situation due to its multiple cardiovascular risk factors. We analyzed 5694 patients in COREA-AMI (COnvergent REgistry of cAtholic and chonnAm university for AMI), to evaluate risk factors of AMI in young patients and to find out long-term outcome. SUBJECTS and METHODS In 2011, 5694 patients were registered in COREA-AMI registry. The patients were divided into two groups. Younger age group I (age<40yrs; n=194; mean age 35.3짹3.5) and older age group II (age>40yrs; n=5500; mean age 64.0짹11.6). Baseline characteristics, predictive factors for MACE, long-term outcome were compared between two groups. RESULTS Baseline characteristics of age, gender, BMI were significantly different between two groups (p<0.001). Also risk factors (hypertension, DM, smoking, family history) were different (p<0.001). In laboratory findings, creatine, hemoglobin, total cholesterol, triglyceride, LDL, initial NT-proBNP, peak CK-MB before PCI were significantly different. In angiographic findings, left main disease and type B2/C lesion were more frequent in Group I (p=0.015, <0.001). By using multiple logistic regression analysis, predictive factors for MACE in young patients were found. BMI, hemoglobin, initial NT-proBNP, DM, previous MI history, and aspirin, clopidogrel, beta-blocker usage after discharge were independent factors of MACE. Clinical outcome of group I were better than group II in MACE-free survival (p=0.06). CONCLUSION Although patient with younger age (less than 40) in AMI had more favorable long-term outcome than older age, use of medication after discharge were found to be independent predictors in COREA-AMI, suggesting that medical therapy should not be underestimated in young patients.