BNP and NT-proBNP are new markers with potential applications for the diagnosis and management of patients with cardiovascular diseases. In patients with acute dyspnea, these markers might strengthen the clinical suspicion of decompensated congestive heart failure. Vice versa, below-threshold marker concentrations allow to virtually exclude significant left ventricular dysfunction in symptomatic patients. Furthermore, BNP and NT-proBNP are predictors of morbidity and mortality in patients with heart failure, but also in acute coronary syndrome, myocardial infarction, pulmonary embolism and other cardiovascular diseases. The markers therefore appear suitable for additional risk stratification. Independently from the clinical application, however, it is important to note that extracardiac variables may affect marker concentrations and need to be considered when marker concentrations are interpreted. Due to their diagnostic and prognostic value, the cardiac markers BNP and NT-proBNP have a clear potential to further improve the care of patients with cardiovascular diseases.