Background: Long-term effects of early initiation of statins in patients with acute myocardial infarction (AMI) on a secondary cardiac events remain unclear. Objectives: The aim of this study was to evaluate the beneficial effects of early initiation of statins on mid-term clinical events after AMI in a real-world setting. Methods: Between October, 2005 and December 2006, 621 patients with AMI (439 ST segment elevation MI and 182 non-ST segment elevation MI) were registered and followed prospectively. Early initiation of statins was defined as prescription during hospitalization (statin group: 545 patients), and the control group was not prescribed statins during hospitalization or at discharge (76 patients). The primary end point was 6-month mortality. Results: During 6-month follow-up, 22 patients died (3.5%), including 7 patients (9.2%) from the control group and 15 patients (2.8%) from the statin group (p=0.004). Although there was no significant difference in 6-month follow-up target lesion revascularization rate [statin group: 63 (11.6%) vs. control group: 11 (14.5%), p=0.463], 6-month follow-up major adverse cardiac events (including cardiac death, MI, and target lesion revascularization) occurred less frequently in patients who were taken early statin therapy compared with patients who were not taken statin therapy [statin group: 78 (14.3%) vs. control group: 18 (23.7%), p=0.034]. Multivariate logistic regression analysis showed that early initiation of statin therapy and elevated high-sensitivity C-reactive protein level were the independent predictors of 6-month mortality [Hazard ratio (HR): 0.029; p=0.037, and HR=3.790; p=0.039, respectively). Conclusions: High inflammatory status is associated with poor prognosis, and early initiation of statins immediately after AMI could decrease mid-term mortality rate.