BACKGROUND It is often argued that adolescents who become pregnant do not sufficiently appreciate the negative consequences, and that prevention programs should target participants' attitudes toward pregnancy. METHODS Data from the first two waves of the National Longitudinal Study of Adolescent Health were used to examine whether 15-19-year-old females' attitudes toward pregnancy influence their contraceptive consistency and their risk of pregnancy. Characteristics and attitudes associated with pregnancy and contraceptive use were assessed using bivariate and multivariate analysis. RESULTS Twenty percent of female adolescents were defined as having antipregnancy attitudes, 8% as having propregnancy attitudes and 14% as being ambivalent toward pregnancy; the remainder were considered to have mainstream attitudes. Among sexually experienced adolescents, having an attitude toward pregnancy was not associated with risk of pregnancy. However, those who were ambivalent about pregnancy had reduced odds of using contraceptives consistently and inconsistently rather than not practicing contraception at all (odds ratios, 0.5 and 0.4, respectively). Antipregnancy respondents did not differ from proprepregancy respondents in terms of their contraceptive consistency. However, having a positive attitude toward contraception was associated with increased likelihood of inconsistent and consistent contraceptive use compared with nonuse (1.6 and 2.1, respectively). CONCLUSIONS Programs designed to prevent pregnancy need to give young women information about pregnancy and opportunities to discuss the topic so that they form opinions. Furthermore, programs should emphasize positive attitudes toward contraception, because effective contraceptive use is shaped by such attitudes and is strongly associated with reduction of pregnancy risk.