Research Findings: Family conflict is known to be associated with poor development for young children, but many children appear resilient. This study examined the extent to which high-quality center care during early childhood protects children from these negative consequences. Children participating in center-based sites of the Early Head Start (EHS) Research and Evaluation study were grouped based on their treatment status: 305 children receiving EHS services, and 305 children not receiving EHS services. Family conflict was positively associated with aggressive behavior as reported by parents for children at 3 and 5 years of age for comparison children but not for children in EHS center-based programs. However, moderation impacts were not observed for objective ratings of child negativity to parent in semistructured interactions. Practice or Policy: These findings may suggest that attending lesser quality child care and living in a family characterized by conflict is associated with heightened aggressive behavior for children aged 3 and 5, whereas attending high-quality child care such as that provided by EHS may buffer the negative impacts of family conflict on children's psychosocial outcomes. (Contains 2 tables.)