Background: Angiotensin-converting-enzyme inhibitors (ACE-Is) reduce major adverse cardiovascular events (MACE) in patients with acute myocardial infarction (AMI). In the previous randomized clinical trials, angiotensin II receptor blockers (ARBs) were as effective as ACE-Is in reducing MACEs. However, it has not been known the impact of these clinical trials in real world practice. We compared the effects of ARBs to ACE-Is on the MACE in Asian post-MI patients. Methods: Between November 2005 and January 2008, 6781 post-MI patients were included from the Korea AMI Registry. Patients who had already received ACE-Is or ARBs before hospitalization were excluded. The primary endpoints were in-hospital mortality and 1 year MACEs. The MACEs were defined as death and recurrent myocardial infarction. Results: Among patients, the prescription rate of ARBs on admission or at discharge was 12.2%. For each patient, a propensity score indicating the likelihood of ARBs use during hospitalization or at discharge was calculated using a non-parsimonious multivariable logistic regression model, and was used to 1:4 match 715 ARBs patients with 2860 ACE-Is patients. Effects of ARBs on in-hospital mortality and 1 year MACEs were assessed using matched logistic and Cox regression models. In logistic regression model, the in-hospital mortality was significantly lower in ARBs patients compared with ACE-Is patients (1.3% versus 3.3%; odds ratio [OR] 0.379, 95% confidence interval [CI] 0.190–0.756; p=0.006). In Cox proportional-hazards model, there were no significant differences between ARBs therapy and ACE-Is therapy in the rate of 12-month MACE (3.4% versus 3.7%; hazard ratio [HR] 0.911, 95% confidence interval [CI] 0.584–1.420; p=0.680) and mortality (3.1% versus 3.1%; HR 1.012, 95% CI 0.633–1.617; p=0.960) in hospital survivors. The 12-month MACE was significantly lower ARBs patients compared with ACE-Is patients (4.6% versus 6.9%; HR 0.661, 95% CI 0.457–0.956; p=0.028). The difference of 12-month mortality between ARBs (4.3%) and ACE-Is (6.2%) patients was marginal (HR 0.684, 95%CI 0.467–1.002; p=0.051). Conclusions: The in-hospital mortality and 1 year MACEs were significantly higher in ACE-Is users compared with ARBs users in Asian population in real world practice. More randomized controlled trials are required in Asian population.