Serum cholesterol changes after an 8-week behavior modification program for patients with coronary artery disease (CAD) were studied in a randomized controlled clinical trial. Acute myocardial infarction (AMI) or coronary artery bypass grafting (CABG) patients were randomly assigned to the intervention (N = 94) or to usual care (N = 90). After 9 months' follow-up the intervention was effective in reducing total cholesterol and LDL cholesterol levels, particularly in patients with high baseline lipid levels. After correcting for changes in dose of statins during follow-up, effects were weakened, but for patients with high baseline cholesterol levels favorable effects remained. In these patients, the intervention group showed a decline of total cholesterol and LDL cholesterol levels of 20% and 29%, respectively, compared to a 12% and 19% reduction in the control group (p <.01). These effects could not be explained by changes in dietary fat consumption. An unexpected finding was a lower increase in HDL cholesterol in the intervention group than in the control group.