The aim of the study was to determine the value of brain natriuretic peptide for the identification of diastolic dysfunction status in congestive heart failure. We studied 204 patients with stable heart failure. Brain natriuretic peptide plasma levels were correlated with echocardiographic parameters of diastolic dysfunction. Diastolic dysfunction was classified as mild (abnormal echocardiographic relaxation pattern) and severe (pseudo-normal or restrictive pattern). A significant correlation between brain natriuretic peptide levels and the other parameters was detected. Brain natriuretic peptide dosage, then, seems to be a reliable tool for the assessment of diastolic dysfunction status in patients with congestive heart failure.