Background : It is well-known that B-type natriuretic peptides (BNP) levels are elevated in patients with significant coronary artery disease even without LV systolic dysfunction. We evaluated whether the BNP levels have additive value on diagnostic accuracy of technetium-99m tetrofosmin single photon emission computed tomography (SPECT) in detecting significant coronary artery disease (CAD) in patients with normal LV systolic function and no regional wall motion abnormality in echocardiography. Methods : A total of 103 patients who were referred for coronary angiography (CAG) due to chest pain were analyzed. SPECT was performed to all the patients before CAG and baseline BNP levels were analyzed with angiographic, clinical and SPECT findings. Result : The clinical diagnosis was stable angina (n=67), unstable angina (n=20), variant angina (n=6) and atypical chest pain (n=9). 64 patients (63 %) had significant CAD and 52 patients (51 %) undergo revascularization (PCI or CABG). SPECT showed good sensitivity (75 %) but low specificity (54%) for diagnosing CAD and also good sensitivity (75 %) and low specificity (45%) for predicting revascularization. Patients with atypical chest pain or variant angina showed significantly lower BNP levels than typical angina patients (P <0.05). In stable and unstable angina (87 patients), BNP levels were significantly higher according to CCS class and angiographic severity (P<0.05). BNP were significantly higher in patients with reversible perfusion defect (PD) on LAD territory than LCX or RCA (P<0.05) and significantly correlated with the degree of reversible PD (r=0.302,P< 0.01). In multivariate analysis, BNP level(>33 pg/ml) was independent predictor for revascularization [OR 3.229 95% CI (1.098-9.498) p=0.33)].In patients with reversible ischemia on LCX or RCA territory (n=37), BNP levels with cut-off value of 30.0 pg/ml shows 60 % sensitivity and excellent 91% specificity for significant coronary artery disease (0.778, 95% CI. 0.622-0.935 p<0.01). Conclusions: BNP correlates with the degree of reversible myocardial ischaemia and predicts revascularization. Low BNP level in patients with reversible PD on RCA or LCX on SPECT highy suggest false postive.