The National Guidelines for Comprehensive Sexuality Education were developed by a Sex Information and Education Council of the United States (SIECUS) task force made up of health, education, and sex education professionals. The group was tasked with formulating sex education concepts and guidelines within four developmental levels, from kindergarden through high school, to provide classroom teachers with a theoretical basis for daily programs, Following a discussion of the goals and values of sex education, the main body of the document focuses on six key concepts: human development (reproductive anatomy, reproduction, puberty, body image, and sexual identity); relationships (families, friendship, love, dating, marriage, and parenting); personal skill (decision making, communication, assertiveness, and negotiation); sexual behavior (masturbation, abstinence, human sexual response, fantasy, and sexual dysfunction); sexual health (abortion, sexually transmitted diseases, HIV infection, and reproductive health); and society and culture (gender roles, sexuality in the law and religion, and sexual diversity). Tables displaying key concepts and a topical outline are provided. (LL)