Background: The role of conventional cardiovascular risk factors in young persons is incompletely understood because only fragmentary data are available. The purpose of this study is to identify the risk factors, clinical and of coronary angiographic findings in young and elderly patients. Methods: We reviewed consecutive 30 young (below 40 years) and 138 elderly (65 years and over) patients with clinical diagnosis of AMI. The differences in the risk factors, clinical characteristics and coronary angiography findings were analyzed between two groups. Results: Compared with elderly patients(young vs elderly), the risk factors of smoking (66.7% vs 26.8%, p<0.001) and male gender (96.7% vs 40.6%, p<0.001) were more frequently found in young patients, but the rates of hypertension (26.7% vs 39.9%, p=0.176) and diabetes( 13.3% vs 34.8%, p=0.123) were lower without statisticaly significance. The body mass index(BMI) was higher in young patients (24.8짹3.3 vs 23.3짹3.2 kg/m² ,p=0.036). Dyspnea NYHA class III or IV was more frequent in elderly patients (0% vs 15.9%, p=0.003). The levels of initial white blood cell counts (WBC) (1.3짹3.4��10³ vs 10.9짹4.0��10³/ml, p=0.003), Hematocrit (43.3짹3.8% vs 37.4짹6.5%, p<0.001) and triglyceride (211.0짹215.1 vs 124.4짹74.9mg/dl, p<0.001) were significantly higher, while uric acid(6.2짹2.3 vs 5.3짹2.0mg/dl, p=0.044) was lower in young patients than in elderly patients. Coronary angiography finding revealed the incidence of multi-vessel diseases was more frequent in elderly patients (23.3% vs 56.2, p=0.001), TIMI flow grade 0or I was more frequent in young patients (73.4% vs 64.1%, p=0.048). Proximal reference diameter of infarct related artery was higher in young patients. Conclusion: Smoking, overweight, male gender, Hematocrit, WBC, triglyceride, coronary flow limitation, size of infarct related artery are more frequent or higher in young patients. The heart failure, uric acid and multi-vessel diseases are frequent or higher in elderly patients.