Abstract: AIM: To investigate the value of NT-proBNP in evaluating left ventricle (LV) diastolic function (DF) of acute myocardial infarction (AMI) patients by echocardiography. METHODS: Sixty-six AMI patients with normal LV systolic function were enrolled and NT-proBNP was determined. LVDF was evaluated by tissue Doppler imaging (TDI) and mitral inflow pulse Doppler. According to the LVDF evaluated by echo indexes, patients were divided into four groups: group A normal LVDF (n=16), group B mild LV diastolic dysfunction (DD) (n=21), group C moderate LVDD (n=24), and group D: severe LVDD (n=5). Patients were followed-up for 12 months and clinical endpoints were rehospitalization caused by exacerbating heart failure or reinfarction, and cardiac death. RESULTS: With increased degree of LVDD, the level of NT-proBNP was significantly elevated (P<0.01). The NT-proBNP level=962.1 μg/L had sensitivity and specificity values of 76% and 73%, respectively, on determining LVDD, independent of other factors. NT-proBNP levels among patients with end events after 12 months and those patients without were significantly different (P<0.05). CONCLUSION: Postinfarction NT-proBNP level can be used independently to evaluate LVDD and predict prognosis and can be used in the risk stratification of AMI patients and for guidance of clinical management.