Coronary artery disease remains the leading cause of death in the United States. To date, management has relied mainly on invasive approaches–coronary artery bypass graft and cholesterol-lowering pharmacotherapy. The Lifestyle Heart Trial was designed to investigate the potential for halting and even reversing coronary atherosclerosis through a regimen of diet, exercise, and stress reduction. As described in this article, these lifestyle measures can produce significant clinical improvement in patients with established disease, at less risk and lower cost than can be acheived by conventional medical-surgical means. While the regimen calls for far greater restriction of dietary fat than is suggested in most guidelines, the positive results obtained are highly encouraging in terms of both prevention and treatment of coronary artery disease.