Many patients with heart failure have stiff hearts with an increased wall thickness and small volumes leading to diastolic dysfunction. Different definitions for diastolic heart failure have been proposed but today there is no generally accepted definition and there are few large controlled studies telling us how it should be managed. Natriuretic peptides (BNP or NT-proBNP) might be used to detect patients with diastolic dysfunction especially in those patients having a restrictive filling pattern or pseudo-normalised mitral flow pattern and in those, who are symptomatic. However, patients with relaxation abnormalities and mild symptoms or asymptomatic may have normal levels of the natriuretic peptides indicating no or only slight elevation of the left ventricular filling pressures. Thus low levels cannot be used as a rule out diagnosis of diastolic dysfunction.