Spending leisure time with deviant peers may have strong influences on adolescents' delinquency. The current 3-wave multi-informant study examined how parental control and parental prohibition of friendships relate to these undesirable peer influences. To this end, annual questionnaires were administered to 497 Dutch youths (283 boys, mean age =13years at baseline), their best friends, and both parents. Cross-lagged panel analyses revealed strong longitudinal links from contacts with deviant peers to adolescent delinquency, but not vice versa. Parent-reported prohibition of friendships positively predicted contacts with deviant peers and indirectly predicted higher adolescent delinquency. Similar indirect effects were not found for parental control. The results suggest that forbidden friends may become "forbidden fruit," leading to unintended increases in adolescents' own delinquency. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc..