Background: Left ventricular hypertrophy (LVH) is strongly associated with cardiovascular morbidity and mortality, independent of blood pressure. LVH is also a prognostic marker for detecting the short- and long-term outcome of patients with acute myocardial infarction (AMI) receiving thrombolytic therapy. The aim of this study was to investigate whether echocardiogrhaphic (2D Echo)-based LVH was an important predictor of mortality in patients with AMI. Methods: From November 2005 to December 2006, 439 consecutive AMI patients (mean age 67.1 짹 11.8 years, 292 men) with available 2D echo results were included in this retrospective study. LVH was defined as left ventricular wall thickness which was measured with echocardiogram over 1.0 cm in female or over 1.1cm in male. In-hospital mortality, and long-term follow-up MACE including all-cause death, target vessel revascularization, non-fatal myocardial infarction were evaluated. Results: Ninety-six patients (21.9%) had LVH, which was more often present in female than male (27.9% vs 18.8%, P=.030). LVH was associated with more often past history of hypertension, older age, higher E/E���, more extended left atrium dimension, and higher level of blood urea nitrogen as well as N-terminal pro-brain natriuretic peptide. Patients with LVH had more often in-hospital death (7.3% vs 0.9%, P=.001), long-term follow-up all-cause death (14.6% vs 4.7%, P=0.001), and long-term follow-up MACE (25.0% vs 15.7%, P=0.036). In Kaplan Meier survival curve, patients with LVH showed worse long-term follow-up death and worse long-term follow-up MACE (P=.036, P<.001, respectively). In Multivariate analysis, LVH was an independent prognostic factor of long-term follow-up all-cause death (Odds ratio (OR)= 5.35, P=.012), though that was not an independent prognostic factor of long-term of follow-up MACE (P=NS). Conclusions: LVH is associated with in-hospital death, long-term follow-up all-cause death, and long-term follow-up MACE. LVH is a useful prognostic factor of long-term follow-up death.