Adolescent pregnancy and parenting remains a pressing social and public health concern because the United States continues to have the highest teen pregnancy rate among Western developed nations and because of the attendant social, psychological, and physical problems for young parents and their children. Prevention efforts to reduce the incidence of pregnancy and parenting among all teens continue to be critical. Even though funding constraints may limit the number of programs, it is possible to maximize the effectiveness of those that do exist or are developed. The most effective prevention programs are those based on theoretical models. This paper focuses on common theoretical models in four areas (developmental, perceived control, attitudes/ intentions, and social learning) that can be easily applied to pregnancy prevention program development. After a short description of the theory and a discussion of its use in the literature, the theory's relevance to pregnancy/parenting prevention program development is discussed. (Contains 1 note.)