Cardiac natriuretic peptide hormones, atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), are synthesized and secreted by the heart, producing several biological effects, such as natriuresis, vasorelaxation and hypotension. During the last decade these peptides, especially BNP, have received increasing attention as potential markers of cardiovascular disease. Their measurements can be used to diagnose heart failure, including diastolic dysfunction, and using them has been shown to save money. BNP levels can enable the differentiation between dyspnoic patients secondary to ventricular dysfunction and subjects with primary respiratory disorders. Moreover, there is good evidence that natriuretic peptides may have a diagnostic role in arterial hypertension, acute coronary syndromes, pulmonary hypertension, some valvular heart disease and some disorders affecting other systems (diabetes or thyroid disorders). In this paper we discuss the clinical utility of assessment of natriuretic peptide hormones in the diagnosis of various clinical conditions and their use as pharmacological agents.