Parenting is a difficult social role involving sensitivity towards a child's needs, appropriate limit setting, guidance, and more. Attention deficit/hyperactivity disorder (ADHD) symptoms as well as oppositional defiant (OD) and aggressive behaviors create additional challenges for parents, especially if both the parent and child display these symptoms and behaviors. In such cases, parents may experience more emotion dysregulation or stress which may interfere with their ability to provide appropriate discipline. The current study utilized a process-oriented approach to assess the associations of maternal and adolescent ADHD symptoms and OD and aggressive behaviors with dysfunctional discipline, as well as the mediating roles of maternal emotion dysregulation and stress. An indirect pattern of effects was observed such that maternal ADHD symptoms and OD behaviors were associated with maternal emotion dysregulation, which was associated with dysfunctional discipline. Meanwhile, adolescent ADHD symptoms and aggressive behaviors were associated with maternal stress, which was associated with dysfunctional discipline. Clinical implications and future directions are discussed.