Observational and other studies suggest gender-related differences in the incidence and prognosis of heart failure. Women appear to live longer after the diagnosis of heart failure when compared with men. After myocardial infarction, women seem more likely than men to exhibit clinical heart failure. Diabetes appears to promote heart failure to a greater extent in women than in men. Review of data from clinical and epidemiologic studies suggests that men and women may differ in their myocardial adaptation to a variety of cardiac insults. Future investigation is necessary to better define gender-related differences and possible sex-specific therapies for those diseases resulting in heart failure.