Data from the National Longitudinal Study of Adolescent Health (Add Health) were used to examine the impact of parents' behavior on adolescents' sexual experience and contraceptive use. All else being equal, adolescents whose parents engage in risky behaviors are especially likely to be sexually active and to have had sex before age 15. These findings are only partly attributable to the link between parents' risky behaviors (smoking, drinking, driving without seatbelts) and adolescents' risky behaviors (smoking, drinking, delinquent activity, association with substance-using peers). Although parental behaviors are effective predictors of adolescents' sexual activity, they are not effective predictors of contraceptive use or of method choice at first coitus. Overall, parents with low levels of self-efficacy seem to be especially likely to have children at risk of engaging in problem behaviors.