Natriuretic peptides including B-type natriuretic peptide (BNP), N-terminal (NT)-proBNP, and midregional pro-atrial natriuretic peptide (MR-proANP) are the biomarkers of choice in the diagnosis of heart failure. Assays measuring either BNP, NT-proBNP, or MR-proANP are widely available and run on large analysers operating in the central laboratory or as point-of-care options. Natriuretic peptides are considered quantitative markers of haemodynamic cardiac stress and therefore quantitative markers of heart failure itself. The clinical introduction of natriuretic peptides constitutes the most important advance in the diagnosis of heart failure in the last decade.