PIP: Contraceptive methods have helped to reduce the incidence of unwanted pregnancies among married women over the past few decades. Rates for teenagers have not, however, declined commensurately. Instead, greater premarital sex has led to more conceptions and births among teens. Developmental hypotheses suggest that poor teenage contraceptive use stems from characteristics intrinsically related to young age. Situational hypotheses, however, posit that life conditions complicate and impede the adoption of an effective contraceptive program. Social proscriptions against teen sex, the sporadic, unplanned, nature of teen sexual encounters, limited knowledge at the onset of 1st sex, and limited mobility and access to contraception are such life conditions. This essay considers both developmental and situational interpretations of teen contraceptive practice. Factors discussed related to contraceptive use include race and socioeconomic status, marital status, educational aspirations, religion, knowledge of fertility and contraception, attitudes and beliefs about contraception, personality factors, influence of parents, peers, and partners, and age. Adults and teens are found to have similar determinants of contraceptive behavior. Contraceptive use behavior differences between adults and teens may therefore exist because sexually active teens are disproportionately represented in demographic groups most likely to take risks. Adolescents being generally single, of low personal income, and increasingly members of single parent homes, share demographic circumstances of adults who are also more prone to risk-taking behavior. Limited knowledge of contraceptives and comparatively high levels of sex guilt further predispose youths to taking risks. Teenagers are therefore more likely to experience as a group those factors predisposing them to early sexual initiation and poor contraceptive use, thereby suggesting a situational interpretation of age differentials in contraceptive use. Adults similar to teens in adult life are similarly likely to take contraceptive risks.