This study addressed ways in which poverty factors are associated with child physical aggression and how these relationships are moderated by parenting behavior. Using a longitudinal approach, parental poverty status was measured when children were 5 months; the Parenting Behaviour Questionnaire (Boivin et al., 2000) was administered when children were 17 months; and mothers reported child physical aggression behaviors when the children were 60 months. Using structure equation modeling analyses, the results of this study confirmed that parenting behavior is a mediator of the linkage between poverty and child physical aggression, showing the urgent need for early intervention for impoverished children.