Abstract: AIM:To investigate the association between serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and the severity of coronary artery lesions. METHODS: Serum NT-proBNP concentrations and left ventricular ejection fraction (LVEF) were measured in 150 patients with chest pain. All patients underwent coronary artery angiography (CAG). Severity of coronary artery lesions was estimated by coronary angiographic Gensini score. According to clinical data and results of CAG, 78 patients were diagnosed with ACS, 33 patients were diagnosed with stable angina (SA) and 39 patients were normal controls. Correlations of NT-proBNP levels with LVEF and Gensini score were analyzed. RESULTS: Serum NT-proBNP concentrations were higher in ACS patients than those in SA patients and control subjects (P<0.05, respectively). A significant difference was observed in NT-proBNP levels between SA patients and control subjects (P<0.05). NT-proBNP levels were correlated with the Gensini score in ACS (r=0.83953, P=0.0001) patients. Multiple stepwise regression analyses revealed that initial NT-proBNP levels were correlated with LVEF and Gensini score in ACS patients. Partial R2 of LVEF and Gensini score in ACS patients was, respectively, R2=0.8327 (P=0.0001) and R2=0.0034 (P=0.1035). NT-proBNP concentrations increased with the severity of coronary artery lesions in ACS group. CONCLUSION: Serum NT-proBNP level is correlated with the severity of coronary artery lesions and has significant prognostic value in ACS patients.