The most important advance in heart failure during the past decade has been the recognition that medications inhibiting neurohormonal activation relieve symptoms, reduce hospitalizations, and prolong survival in patients with heart failure from left ventricular systolic dysfunction. Recent trials with angiotensin-converting enzyme inhibitors, angiotensin receptor antagonists, aldosterone antagonists, and beta blockers have provided valuable information regarding the uses, dosing, and extent of therapeutic benefits of neurohormonal inhibition.