Natriuretic peptides are increasingly used as biomarkers for several clinical entities. An overview of the clinical applications of brain natriuretic peptide (BNP) and N-terminal brain natriuretic peptide (NT-proBNP) is presented. These neurohormones are used for diagnosis, monitoring and predicting prognosis in patients with chronic heart failure. The indications extend to risk stratification and prognosis of acute coronary syndromes and prognosis of acute pulmonary embolism. An appraisal of the influence of beta-blockers and other drugs in the measurement of natriuretic peptides is performed. The clinical effectiveness of treatment with the cardiac hormone nesiritide (human B-type natriuretic peptide) in heart failure is assessed.