This paper examines the application of social learning theory (SLT) in large-scale studies designed to investigate the effects of dietary intervention in the lowering of plasma cholesterol level and prevention of coronary heart disease (CHD). Several SLT-based intervention methods are reviewed including behavioral self-regulation techniques, group approaches and family involvement. The Family Heart Study intervention is described in detail, with a particular focus on efforts to promote dietary lifestyle change using a family-based group approach. The implications for present and future CHD prevention projects and dietary intervention studies aimed at lowering plasma cholesterol levels are discussed.