Background: This study was aimed to evaluate the validity of the Global Registry of Acute Coronary Event (GRACE) and B-type natriuretic peptide (BNP) in patients with acute coronary syndrome (ACS). Methods: One thousand three hundreds eight patients (63.6짹12.0 years, 921 male), who were admitted at coronary care unit (CCU) of Chonnam National University Hospital between January 2004 and December 2005, were analyzed. The patients were divided into two groups: the survived group (Group I: n=1,298, 871 male, 63.1짹9.7 years) and the moribund group (Group II: n=80, 50 male, 67.4짹8.5 years). Clinical characteristics, risk factors for atherosclerosis, echocardiographic findings, GRACE score and NT-proBNP were compared between the two groups. Results: The overall mortality was 5.8 %, 80 out of 1,378 patients. Mortality was higher in patients with Killip IV (46.7 %, 50 out of 107 patients) than Killip ��� or ��� and elderly patients more than 80 years (42.7 %, 38 out of 89 patients). High Killip class and old age were associated with high mortality (p<0.0001 respectively). Total score of GRACE was elevated in group II (142짹40.3 vs. 240짹40.0) and high GRACE score was significant predictor of mortality (p<0.0001, r=0.827). Sensitivity, specificity, positive and negative predictability of GRACE score were 73 %, 94 %, 74 % and 93 %, respectively. The level of NT-proBNP was 2181.6짹5396.0 pg/mL in group I and 9954.4짹12820.0 pg/mL in group II (p<0.001). The level of NT-proBNP was correlated with mortality (p<0.001, r=0.270). Conclusions: GRACE score and NT-proBNP level are useful predictors for the mortality of ACS.