According to spillover theory (Engfer, 1988), disruptions in one relationship (e.g., interparental) may lead to perturbations in another (e.g., parent-child), and these boundary disturbances have been linked to child psychopathology. Yet few studies have explored spillover from both constructive and destructive interparental conflict in relation to children's symptoms of psychopathology, and fewer have differentiated mothers' and fathers' parenting in these investigations. Thus, the purpose of the current study was to explore mothers' and fathers' problematic parenting practices-specifically, their inconsistent discipline, unsupportive reactions, and control through guilt-as indirect pathways between constructive and destructive interparental conflict and children's internalizing and externalizing symptoms. Two sequential mediation models were constructed-one for destructive interparental conflict and another for constructive interparental conflict-using 3 waves of data collected annually beginning when children (N = 235) were approximately 6 years old. Direct effects of the 2 models showed that constructive conflict was associated with lower levels of problematic parenting practices, whereas destructive conflict was associated with higher levels. Indirect effects findings showed that mothers' control through guilt was an explanatory mechanism between constructive and destructive interparental conflict and children's externalizing symptoms, whereas mothers' unsupportive reactions were a significant intermediary process between constructive interparental conflict and children's internalizing symptoms. Therefore, results of the current study support the spillover hypothesis and suggest that differentiating mothers' and fathers' problematic parenting practices-as well as distinguishing between constructive and destructive interparental conflict-remain important, as each can have distinct relations to child adjustment. (PsycInfo Database Record (c) 2020 APA, all rights reserved).