Prior research links poor maternal emotion regulation to maladaptive parenting and child behaviors, but little research is available on these relationships during the adolescent period. We use structural equation modeling to assess the influence of poor maternal emotion regulation, measured as emotional reactivity and distancing, on adolescent behaviors (measured as aggression and prosocial behaviors) among 478 adolescents (53 % female; baseline age 10–13 years) and their mothers over a 5 year period. We also tested the possible mediating roles of family functioning and parenting behaviors between maternal emotion regulation and adolescent behaviors. Results indicated that higher baseline maternal emotional distancing and reactivity were not directly predictive of adolescents’ behaviors, but they were indirectly related through family functioning and parenting. Specifically, indulgent parenting mediated the relationship between maternal emotional reactivity and adolescent aggression. Maternal-reported family functioning significantly mediated the relationship between maternal emotional distancing and adolescent aggression. Family functioning also mediated the relationship between emotional distancing and regulation parenting. The results imply that poor maternal emotion regulation during their child’s early adolescence leads to more maladaptive parenting and problematic behaviors during the later adolescent period. However, healthy family processes may ameliorate the negative impact of low maternal emotion regulation on parenting and adolescent behavioral outcomes. The implications for future research and interventions to improve parenting and adolescent outcomes are discussed.