Natriuretic peptides (NP) are quantitative plasma biomarkers of heart failure, which are widely used in clinical practice in many countries. NP levels are accurate in the diagnosis of heart failure in patients presenting with dyspnea. The use of NP improves patient management and reduces total treatment costs in patients with dyspnea. As NP levels quantify disease severity in patients with established heart failure, NP levels are powerful predictors of outcome in predicting death and rehospitalization. NP-guided therapy may improve morbidity in patients with chronic heart failure. Although NP levels also risk-stratify patients with many other conditions such as stable or unstable coronary artery disease, pulmonary embolism and community-acquired pneumonia, there is insufficient evidence on how patient outcome could be altered in patients identified as high risk.