Identification of accurate predictors of mortality in patients with heart failure is important in making rational treatment decisions as well as in the design of clinical trials. The following four categories of variables have been found to be independent predictors of mortality: 1) functional capacity, 2) hemodynamic measures of cardiac pump performance, 3) spontaneous arrhythmias, and 4) laboratory evidence of neurohormonal activation. Within each category, multiple variables are predictive and are correlated with each other. These variables are operative only over a 1- to 5-year time period. Most patients with clinically manifest heart failure undergo inexorable disease progression and die within 10 years of diagnosis, despite important recent advances in the pharmacologic treatment of this syndrome.