This study examined the effects of reported maternal and paternal support, psychological control, and spanking on externalizing behavior of toddler boys. Questionnaires were administered to both parents of 104 two-parent families with a 3-year-old son. Both maternal and paternal psychological control was related to boys' externalizing behavior. Interaction effects were found, in that the association between maternal spanking and boys' externalizing behavior was stronger when levels of maternal support were high. High levels of paternal support strengthened the association between maternal support and boys' externalizing behaviors. Results suggest that the associations between specific parenting dimensions and children's externalizing behavior need to be considered within the context of other parenting dimensions that are displayed within the family.