With 550,000 new cases each year, congestive heart failure is a major medical problem. Several medical therapies, including digoxin, angiotensin-converting enzyme inhibitors, and beta-blockers, have reduced the number of re-hospitalizations and slowed the progression of congestive heart failure. Angiotensin-converting enzyme inhibitors, some beta-blockers, and the combination of hydralazine with nitrates have improved survival. Despite these benefits, medical therapy frequently fails to improve quality of life. Biventricular pacing has been introduced to resynchronize mechanical and electrical asynchrony frequently observed in patients with heart failure. The most recent pacing trials show an improvement in quality of life and functional class. Long-term data are needed to determine the effect of biventricular pacing on survival. The acute hemodynamic studies suggest that resynchronization pacing therapy may predict a positive long-term benefit for many patients with congestive heart failure.