Adolescent association with deviant and delinquent friends was examined for its roots in coercive parent-teen interactions and its links to functional difficulties extending beyond delinquent behavior and into adulthood. A community sample of 184 adolescents was followed from age 13 to age 27, with collateral data obtained from close friends, classmates, and parents. Even after accounting for adolescent levels of delinquent and deviant behavior, association with deviant friends was predicted by coercive parent-teen interactions and then linked to declining functioning with peers during adolescence and greater internalizing and externalizing symptoms and poorer overall adjustment in adulthood. Results are interpreted as suggesting that association with deviant friends may disrupt a core developmental task-establishing positive relationships with peers-with implications that extend well beyond deviancy-training effects.