Background: Statins reduce mortality of patients with coronary artery disease. However, many trials have excluded patients with ischemic heart failure (IHF). Objectives: The aim of this study was to determine the effects of statin therapy in patients with IHF. Methods: We studied 202 patients with IHF who underwent percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) [left ventricular ejection fraction (LVEF) below 40%] between January 2001 and June 2002. The patients were divided into two groups: Group I (n=106, 60.8짹10.3 years, men 71.7%) who were treated with simvastatin and Group II (n=96, 60.9짹10.4 years, men 78.1%) who were not treated with simvastatin. Results: At six-month after PCI, the lipid profiles and inflammatory markers were improved significantly in Group I than in Group II and the LVEF was improved significantly in Group I than in Group II (30.8짹10.0% to 42.4짹10.7% vs. 31.9% to 38.9%, p=0.042). During one-year clinical follow-up, statin therapy was associated with a significant reduction in mortality (1.9% vs. 7.5%, p=0.048), restenosis rate (25.7% vs. 43.1%, p=0.033) and repeat PCI rate (25.7% vs. 43.1%, p=0.033). The event-free survival rate was higher in Group I than in Group II (79.8% vs. 57.0%, p=0.001). The independent predictors for one-year major adverse cardiovascular events were high C-reactive protein and old age, but statin therapy was not an independent predictor for MACE. Conclusion: Statin therapy improves LV systolic function and decreases mortality, restenosis and repeat PCI rate in patients with IHF who underwent PCI for AMI.