The influence of family values on adolescent problem behaviors is explored in an 18-year study of 199 families. Factor analyses revealed two value dimensions: traditional/achievement and humanistic/egalitarian. Problem behavior was indicated by drug use, delinquency, dropout, and sexual behavior. Maternal values predicted similar adolescent values. Traditional values generally protected adolescents against problem behaviors. Humanistic/egalitarian values protected against delinquency but increased drug use risk. Maternal countercultural identity protected adolescents against hard drug use.