Purpose: To assess the usefulness of plasma N-terminal pro B-type natriuretic peptide (NT-proBNP) for predicting adverse outcomes in patients whose first clinical manifestation was dilated cardiomyopathy (DCM). Methods: From March 2003 to April 2008, we evaluated 279 consecutive patients whose first clinical manifestation was DCM. All patients had undergone blood test for plasma NT-proBNP level and echocardiographic examination at the time of diagnosis and at 3-6 months, 1 year and then annually. Study subjects were followed-up with clinical end-point defined as cardiovascular death and hospitalization for heart failure. Results: Follow-up period was 736 짹 31 days (39-860 days). In 90 (32.3%) patients, clinical end-points occurred (cardiovascular death [n=37] and hospitalization of heart failure [n=53]). In univariate analysis, initial ejection fraction on echocardiography, serum sodium level, and serial plasma NT-proBNP levels were associated with clinical end-points. In multivariate analysis, only mid-term plasma NT-proBNP level was related with end-point. The optimal cut-off value of the mid-term plasma NT-proBNP level was 1000 pg/ml (area under curve 0.787, sensitivity 0.776, specificity 0.710). The event-free survival was significantly lower in patients with NT-proBNP levels > 1,000 pg/ml(p-value <0.001). Conclusion: The mid-term NT-proBNP level was a strong predictor of adverse outcomes in patients whose first clinical manifestation was DCM. As NT-proBNP levels below 1,000 pg/ml was related with good clinical outcome, this value might be useful as therapeutic monitoring or prognostic guideline for the treatment of DCM. Key word: N-terminal pro brain natriuretic peptide, dilated cardiomyopathy