Evidence suggests that marital aggression and parent-to-child aggression sometimes occur within the same family, but little is known about why certain families are vulnerable to multiple forms of family aggression. According to family systems theory, negative affect in one family relationship can spread to other family relationships. According to family stress theory, aversive circumstances increase families' vulnerability to disruption and conflict. Based on these theories, the present study tests the hypothesis that cumulative family stresses potentiate the association between marital aggression and parents' child abuse potential. In a series of additive interactional models, husband-to-wife aggression was linked to husbands' and wives' child abuse potential in a context of both high financial stress and high parenting stress but was not linked in a context of low stress. Wife-to-husband aggression was linked to wives', but not husbands', child abuse potential in a context of high stress. These results highlight the potential role of contextual factors in the pervasiveness of aggressive exchanges across multiple family subsystems.