Natriuretic peptides, in particular, brain or B-type, are useful for the assessment of patients presenting with dyspnea to the medical office or emergency department. Levels of natriuretic peptides are useful for assessing prognosis of heart failure or coronary syndrome patients. Less is known about serial peptide measurements for guiding treatment strategies in heart failure. The authors review the uses, pitfalls, and practical points for using natriuretic peptides clinically.