In patients with chronic heart failure (HF), amino-terminal pro-B-type natriuretic peptide (NT-proBNP) levels are among the strongest independent predictors of hazard, and their measurement is useful for prognostication across the entire spectrum of HF disease severity. In patients with chronic HF, repeated determinations of NT-proBNP levels appear to convey additional prognostic value for relevant adverse outcomes, including death or HF hospitalization. Although "hard targets" for NT-proBNP values are not entirely defined, morbidity and mortality in chronic HF appear to increase markedly with an NT-proBNP concentration >1,000 ng/L. Confounding factors (such as renal function or obesity) should be kept in mind when prognostically evaluating patients using NT-proBNP measurements; however, the value of NT-proBNP is retained in these patients. Thus, serial assessment of NT-proBNP is valuable for prognostication in chronic HF in outpatients, and, as such, a measurement at each patient visit or the following of changes in clinical stability is recommended.