Background: Left ventricular hypertrophy (LVH) is a strong risk factor for future cardiovascular events of blood pressure levels in patients with essential hypertension and is a part of progressive morphologic LV change after myocardial infarction. The objective of this study was to assess the associated factors of LVH first 6 months after acute myocardial infarction (AMI). Methods: A total of 531 consecutive patients (63.4짹12 years, 388 males) with AMI, who were examined by echocardiography at admission and after 6 months. LVH was defined by calculating from LV mass index and relative wall thickness at six months. They were divided to LVH (n=226, 66.4짹12 years) and non-LVH group (n=305, 62.1짹10 years). LVH concluded concentric remodeling (n=26, 60.6 짹11 years), concentric hypertrophy (n=126, 66.7 짹11 years), and eccentric hypertrophy (n=74, 70.1 짹10 years). Various clinical, laboratory, echocardiographic parameters and coronary angiographic findings were compared among groups. Results: Old age, diabetes and hypertension consisted higher percentage in LVH group than non-LVH group. B-type natriuretic peptide (BNP) and serum glucose level were significantly increased in LVH groups, especially concentric subtype (p<0.05). Low ejection fraction and high ratio of mitral inflow divided by septal annulus tissue Doppler velocity was closely related with LVH. Ischemic mitral regurgitation at admission was more frequently found in LVH group than non-LVH group. In-hospital early complication was significantly associated with LVH, whereas one- year major adverse cardiac event was no significant difference. By multi-variate analysis, BNP was independently related with LVH (Odd ratio=1.965, p=0.003, CI=1.268-3.045). Conclusions: Elevated serum BNP level affects left ventricular morphologic change in patients with AMI.