This review article stresses the importance of prevention in the reduction of the incidence of artherosclerotic disease, especially coronary heart disease. Evidence accumulated from autopsy studies, animal experimentation, and long-term epidemiologic studies supports the concept that atherosclerosis has its inception in childhood. Adult programs designed to change life styles and attitudes or reverse morphologic changes appear doomed to failure. Therefore, if nutritional, physical activity, and smoking habits are to be altered, it is essential to begin these efforts in infancy and childhood.