Background: Numerous studies have demonstrated that statins reduce major adverse cardiac events (MACE) and improve survivals in patients with acute myocardial infarction (AMI). Moreover, these studies suggest that high-dose statin therapy would be beneficial for reducing clinical events compared to low-dose statin therapy. However, in real-world practice, little is known about the impact of high-dose statin theapy for Asian AMI patients. Methods: Between January 2008 and August 2011, 8,178 statin-naive patients (5,810 men; mean age = 63.5 짹 12.9 years-old) were selected from the Korea AMI registry. The 6-month MACEs were defined as a composite of death, non-fatal MI, and revascularizations. Results: During the 6-month follow-up, 1,068 (13.1%) MACEs occurred. There was no significant difference in 6-month MACEs according to type of statin (atorvastatin 9.8%, rosuvastatin 8.5%, pitavastatin 9.2%, simvastatin 7.9%, pravastatin 8.5%, fluvastatin 9.8%, p = 0.253). In Cox proportional hazards model, the 6-month MACE was significantly lower in statin patients compared with no-statin patients (9.4% versus 22.2%; hazard ratio [HR] 0.776, 95% confidence interval [CI] 0.622–0.968; p=0.025) after adjustment for clinical and angiographic variables. In subgroup analysis, statin users were stratified into two [���10mg (n=1,029) and ���20mg (n=520) for rosuvastatin] or three groups [10mg (n=1,368), 20mg (n=6460, and ���40mg (n=553) for atorvastatin] based on dosage of statin. There was no significant difference in 6-month MACE between high-dose and low-dose rosuvastain users (5.0% versus 5.2%, p = 0.835). However, high-dose atorvastain users (8.1%) had significantly higher 6-month MACEs compared with low- (5.6%) and intermediate-dose (6.3%) atorvastatin users (p = 0.039) in univariate analysis, because high-dose atorvastatin was used more frequently in patients with high-risk features such as cardiogenic shock in baseline characteristics. In Cox proportional hazards model, there was no significant difference in 6-month MACE in high-dose atorvastatin users compared with intermediate- (HR 1.571, 95% CI 0.955-2.587, p = 0.075) and low-dose atorvastatin users (HR 1.579, 95% CI 0.922-2.707, p = 0.096) after adjustment for confounding variables. Cardiogenic shock, multivessel disease, and percutaneous coronary intervention were independent predictors of 6-month MACEs. Conclusions: Although the benefit of statin therapy for reducing 6-month MACE was substantial, there was no significant benefit of high-dose statin therapy improving short-term clinical outcome in patients with high-risk features.