Background: Elevation in B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are associated with symptomatic left ventricular dysfunction. Myocardial ischemia may also cause elevation in level of BNP and NT-proBNP. Methods and Results: To determine whether elevation of NT-proBNP without elevation of cardiac specific marker could predict the coronary artery disease, we measured serum (s) NT-proBNP level in 179 unstable angina patients (61.8짹44.1years, male 60.9%) with normal ventricular function (left ventricular ejection fraction > 55 % and no regional wall motion abnormality by echocardiography) and normal troponin I level (��� 0.05 ng/mL). In these patients, level of CRP, myoglobin and ECG finding are normal. Serum-level of NT-proBNP was higher in patients with coronary artery disease (n=74) than in those without coronary artery stenosis (n=105) (196.8짹339.8 vs. 78.4짹91.0 pg/mL, p=0.005). At the standard cutpoint of > 200 pg/mL, elevated BNP show high probability of coronary artery disease (odd ratio, 2.98; 95% CI, 1.4 to 8.2; p =0.006).We estimated the extent of coronary artery disease by the Gensini score. The Gensini score was computed by assigning the severity score to each coronary, according to the degree of luminal narrowing and its geographic importance. S-level of NT-proBNP was positively correlated with extent of coronary artery disease (r=0.347, p= 0.001). Conclusion: NT-proBNP will be a useful screening test for coronary artery disease in unstable angina patients with normal troponin I value and normal ECG.