DescriptionResearch has established that families of youth with externalizing disorders are characterized by risky parent-child interaction (including high levels conflict and lower levels of both involvement and structure) and parents affected by psychopathology (major depression (MDD) and antisocial behavior (ASB)). However, given mixed results in this field, more comprehensive study of specific family risk factors among the spectrum of externalizing disorders is merited, especially given recent evidence that parental psychopathology and family interaction may be connected. Additionally, parental psychopathologies and risky parent-child interactions were investigated longitudinally, addressing how these family factors influence the persistence of externalizing disorders. Participating families were drawn from the Minnesota Twin Family Study (MTFS), a community-based longitudinal study of twins and their families. Externalizing youth had lifetime diagnoses of CD, ODD, and ADHD; affected parents had lifetime diagnoses of MDD and antisocial behavior (DSM-III-R criteria, American Psychological Association, 1987). Parent-child interaction was assessed by the Parental Environment Questionnaire (PEQ). Youth externalizing was generally related to parental MDD and ASB; with maternal diagnoses more strongly associated than paternal diagnoses. Higher levels of parent-child conflict, lower levels of parent-child involvement, and lower levels of parent-child structure (but not for mothers) were associated with externalizing disorders. Interactions of youth externalizing and maternal MDD indicated lower mother-child involvement for CD/ODD youth was not dependent upon depression. Interactions for externalizing youth and parental ASB similarly indicated that higher parent-child conflict, lower involvement and structure were not dependent upon parental ASB for CD/ODD youth, but may be for ADHD youth. Longitudinal results indicate that lower levels of involvement and higher levels of conflict predict both CD and ODD persistence, but parental ASB was only predictive of CD persistence. Possible mechanisms for the how interaction of youth and parent psychopathologies may relate to changes in parent-child interaction are discussed, including framing findings within a coercion theory model. This framework (Granic & Patterson, 2006) emphasizes that real time coercive parent-child interactions may develop into persistent patterns of rigid interactions over time, which may ultimately affect the child’s developmental trajectory towards future antisocial behavior. Potential pathways to externalizing disorders are discussed.