Using data from the National Longitudinal Study of Adolescent Health, the authors examine the association between contraceptive use patterns in teens' first sexual relationships and their knowledge of, perceptions of, and motivations for contraception and pregnancy prevention. Results from logistic regression analyses show that knowledge, perceptions, and motivations surrounding sexual activity and contraception are indeed important predictors of contraceptive outcomes, and they influence males and females differently. For both genders, perceived ease of access to contraceptives is associated with increased odds of ever using contraception and using contraception consistently. For males, greater perceived condom knowledge is associated with increased odds of ever using contraception. For females, higher levels of actual reproductive health knowledge is associated with increased odds of ever using contraception, and holding negative views of pregnancy and having greater contraceptive self-efficacy are both associated with increased odds of consistent contraceptive use. (Contains 4 tables and 6 notes.)