Background-Although it is recommended that all patients with heart failure (HF) have advance directives (AD) in place before the end of life is imminent, the use of AD in HF has not been well studied. Methods and Results-We enrolled consecutive Olmsted County residents presenting with HF from October 2007 through October 2011 into a longitudinal study. Information from AD completed before enrollment and hospitalizations in the month before death were abstracted. Among 608 patients (mean age, 74.0 years; 54.9% men; 65.3%; New York Heart Association functional class 3 or 4), 164 (27.0%) patients died after a mean follow-up of 1.8 years. At enrollment, only 249 (41.0%) patients had an AD. Although most AD appointed a proxy decision-maker (90.4%), less than half addressed wishes regarding use of cardiopulmonary resuscitation (41.4%), mechanical ventilation (38.6%), or hemodialysis (10.0%) at the end of life. The independent predictors of AD completion were older age (adjusted odds ratio [OR] per 10-year increase, 1.82; 95% confidence interval [CI], 1.51-2.20), malignancy (OR, 1.58; 95% CI, 1.05-2.37), and renal dysfunction (OR for estimated glomerular filtration rate <60 mL/min 1.55; 95% CI, 1.05-2.29). At the end of life, patients with AD specifying limits in the aggressiveness of care less frequently received mechanical ventilation (OR, 0.26; 95% CI, 0.07-0.88), with a trend toward decreased intensive care unit admission (OR, 0.45; 95% CI, 0.16-1.29). Conclusions-Despite a high mortality rate, over half of patients with HF do not have an AD, and existing AD fail to address important end-of-life medical decisions. © 2012 American Heart Association, Inc.