Recent surveys monitoring health behavior in children and adolescents in Europe, Canada and the USA are reporting worrisome data in terms of health-risk behavior. Childhood and adolescence are critical periods in life for taking preventive measures, since this is the time when health-related behavior and lifestyles have their beginnings. The present paper attempts to introduce the art and science of health education with the ultimate goal of stressing the fact that health and education are strongly associated. Approaches to health education, models of intervention and recommendations by leading authors in the field are presented. Suggestions for sex education in children and adolescents are provided.