Heart failure (HF) is a common disease associated with increasing age. B-type natriuretic peptide (BNP), is a cardiac neurohormone, and is released as prepro BNP and then enzyrnatically cleaved to the Ntenninal-proBNP (NT-proBNP) and BNP upon ventricular myocyte stretch. Blood measurements of BNP have been used to identify patients with I-IF. The BNP assay is currently used as a diagnostic and prognostic aid in HF. In general, a BNP level below 100 pg/mL excludes acutely decompensated HF and levels ＞ 500 pg/ml indicate decompensation. Recombinant human BNP (hBNP, nesiritide) is an approved intravenous treatment for acute,decompensated -HF. Nesiritide given in supraphysiologic doses causes vasodilation, natriuresis, diuresis, and improved symptoms over the course of a 48-hour infusion. This paper will sort out the literature concerning the use of this peptide both as a diagnostic test and as an intravenous therapy.