Previous studies which found little relationship between parental norms and adolescent sexual activity have been limited by their failure to recognize developmental differences in the relative weight of parent and peer influences between younger and older teens and by use of selected samples, resulting in a restriction of range. The current study differs in that it utilizes a clustered sample household survey of 329 males and females, aged 14 to 17, and 470 of their parents. Using multiple regression analysis, it was found that parents' reported behavioral norms account for 5 percent of the variance in whether adolescents have had intercourse, and for 33 percent of the variance in use of contraception at last intercourse. The study suggests that while parents' normative beliefs have limited effect in the decision to become sexually active, they have considerable impact on later contraceptive use. 17 references. (Author abstract)