Background/Aims: Renal dysfunction is associated with a higher risk of cardiovascular disease in patients with acute myocardial infarction (AMI). The aim of this study was to investigate the independent prognostic value of renal dysfunction and its incremental predictability risk after adjusting for well-known clinical factors in patients with AMI. Methods: 751 consecutive patients with AMI admitted to the Coronary Care Unit (CCU) were included. Patients were grouped into 2 categories according to the baseline estimated glomerular filtration rate (eGFR) on admission (eGFR <60 vs. eGFR ≧60 ml/min/1.73 m2). C-reactive protein and white blood cell count (WBC) as well as clinical prognostic variables were assessed. The endpoint was mortality during CCU stay. The discriminatory power was estimated by the C-index. Results: The patient group with an eGFR <60 ml/min/1.73 m2 was older, had more cardiovascular risk factors, a lower left ventricular ejection fraction and higher cardiovascular mortality during CCU stay (13 vs. 3%). Logistic regression analysis revealed the following predictors of mortality: degree of renal impairment (eGFR <60 ml/min/1.73 m2), hazard ratio (HR) = 2.2 (95% CI 1.1–4.3; p = 0.028); WBC >11,000 × 106/l, HR = 2.3 (95% CI 1.2–4.5; p = 0.017); Killip class on admission, HR = 3.8 (95% CI 1.7–8.5; p = 0.001), and New York Heart Association Functional Classification, HR = 3.6 (95% CI 1.7–7.4; p = 0.001). The adjusted C-index was 0.78 for baseline clinical variables and 0.84 for eGFR. Conclusions: In patients with AMI, decreased eGFR is an important prognostic factor for impaired cardiac function and mortality in the short-term follow-up. The eGFR may be reliably used in the risk stratification of patients with AMI.