Objective To evaluate the clinical value of N-terminal pro-brain natriuretic peptide (NT-proBNP) detection in elderly patients with acute dyspnea. Methods Based on the etiology, 202 elderly patients with acute dyspnea were divided into three groups: simple pulmonary disease(PD) group(A), simple congestive heart failure(CHF) group (B), and CHF and PD combination group (C). NT-proBNP levels, echocardiogram, left ventricular ejection fraction (LVEF), and New York Heart Association (NYHA) classification were assessed in all subjects. NT-proBNP levels were compared between different groups. Correlations of NT-proBNP levels with NYHA classification and LVEF in group B and C were analyzed. Results NT-proBNP level was significantly lower in group A than in group B and C [(197.5±64.3) vs (1873.9±857.1) and (1952.4±914.8)ng/L, P＜0.01], and was not significantly different between group B and C (P＞0.05). This indicated that NT-proBNP level was significantly higher in patients with cardiac dyspnea than those with pulmonary dyspnea. NT-proBNP level increased gradually in patients with NYHA Ⅱ, Ⅲ and Ⅳ heart function [(562.37±102.4), (2736.72±81.67), (5873.19±127.73) ng/L respectively, P＜0.01], indicating that higher level of NT-proBNP in patients with higher heart functional class. Person linear correlation analysis showed that NT-proBNP level was negatively correlated with LVEF (r= ?0.689, P＜0.01), indicating that higher NT-proBNP level corresponds with lower LVEF and poorer heart function. Conclusion NT-proBNP plays a key role in differential diagnosis of cardiac and pulmonary dyspnea in elderly patients and its level is closely related with the severity of heart failure.