Seventy-five persons (57 male and 18 female) with a high risk of coronary heart disease (CHD) were randomly assigned in equal numbers to three 8-week behavioral treatment programs. All three treatments were designed to alter simultaneously a number of risk-elevating behavior patterns, in the expectation that change in any one behavior pattern would reinforce change in others. Weight, blood pressure, and aerobic fitness were regularly assessed in all subjects. Serum lipids were also measured, but less frequently. All three interventions produced significant beneficial changes in the major objective measures, and the changes were well maintained after 12 months. The most improved group exhibited the following mean changes: weight loss of 9.2 kg, reductions in blood pressure of 12.9/8.8 mm Hg, improvement in aerobic capacity of 33%, reduction in serum cholesterol of 0.45 mmol/liter, and reduction in current overall CHD risk of 41%. The effectiveness of the interventions was positively related to the degree to which the programs emphasized training in, and detailed application of, behavioral change principles.