B-type natriuretic peptide (BNP) is an endogenous cardiac neurohormone, produced in the ventricles in response to pressure and volume elevation. Nesiritide is identical to endogenous BNP and is synthesized using recombinant DNA technology. It is currently used in the treatment of acute decompensated heart failure. In clinical trials, nesiritide has been shown to decrease pulmonary capillary wedge pressure, pulmonary artery pressure, right atrial pressure, and systemic vascular resistance, as well as increase cardiac index and stroke volume index. Infusions of nesiritide have led to increased diuresis and natriuresis. Patients treated with nesiritide have reported improvements in global clinical status, dyspnea, and fatigue. Therapy with nesiritide has resulted in decreased plasma renin, aldosterone, norepinephrine, and endothelin-1 levels, as well as reduced ventricular ectopy and ventricular tachycardia. Heart rate variability also improved with nesiritide. Patients with acute coronary syndromes, serious arrhythmia, renal disease, diastolic dysfunction, or vasopressor dependence have been safely managed with nesiritide. Early treatment with nesiritide in the emergency department may lead to decreased length of hospital stay and reduced readmission rates compared to standard care. Outpatient serial infusions of nesiritide in severe heart failure patients on optimal medical therapy may result in improved clinical status, increased ejection fraction, reduced aldosterone and endothelin-1 levels, and decreased hospitalizations. Potential future uses of nesiritide include treatment of acute coronary syndromes, pulmonary hypertension, bronchospasm in chronic lung disease, and as antifibrotic/anti-remodeling therapy or bridge to cardiac transplant. The possibility of subcutaneous injections of nesiritide has been studied in both animals and humans.