Background: Chronic kidney disease (CKD) is associated with a marked increase in the incidence of atherosclerotic cardiovascular disease (CVD). The aim of this study was to investigate the relationship between chronic kidney disease and long-term prognosis in patients with AMI in Korea. Methods: A 6,207 AMI patients (62.1짹12.4 years, 4,437 males) who were followed up during one year after discharge were divided into three groups according to glomerular filtration rate (GFR), calculated by the Modification of Diet in Renal Disease (MDRD) method ; Group 1 (GFR : ���60 ml/min, n=3,799, 56.5짹10.7 years, 3,105 males), Group 2 (GFR : 30-59, n=1,970, 71.8짹8.6 years, 1,146 males), Group 3 (GFR : <30, n=393, 72.3짹11.5 years, 186 males). We analyzed baseline clinical characteristics, one year major adverse cardiac events (MACE). Results: Age, NT-proBNP levels was higher at the group 3 than at the group 1,2 (p<0.001), and initial Killip class, risk factors such as hypertension, diabetes, ACC/AHA C class lesion, LM disease, three vessels disease was more common at the group 3 than at the group 1,2 (<0.001). Female was more common at group 3 than at the group 1,2 (p<0.001). Left ventricular ejection fraction was lower at the group 3 than at the group 1,2 (p<0.001). One month, six months, one year MACE was more common at the group 3 than at the group 1,2 (p<0.001, p<0.001. p<0.05, respectively) In Cox proportional hazard regression analysis, age (Relative risk (RR) 1.087, 95% CI 1.029-1.061, p<0.001), Initial Killip class >1 (RR 2.282, 95% CI 1.703-3.058, p<0.001), Diabetes (RR 1.328, 95% CI 1.002-1.760, p=0.048), LVEF (RR 0.962, 95% CI 0.951-0.973, p<0.001), GFR < 30 (RR 2.777, 95% CI 1.777-4.339, P<0.001) were significant independent predictors of mortality of patients with AMI. Conclusions: CKD was significant independent predictor of MACE in patients with AMI, and severe decreased GFR (< 30 ml/min) had worse clinical outcomes.