Results from a study of 100 Head Start children and their teachers suggested that teacher-child relationship quality was associated with children's classroom behaviors. Specifically, teacher-child conflict was strongly related to children's externalizing behaviors. Based on these findings, we present recommendations for the development of policies and practices designed to prevent Head Start children's challenging behaviors and promote their social-emotional competence by enhancing the quality of teacher-child relationships. The results of this study suggest that teachers and children could benefit from the following: (a) teacher training and ongoing feedback regarding the identification of young children's challenging behaviors; (b) extensive support, observation, and feedback for teachers regarding their interactions and relationships with children, particularly those exhibiting challenging behaviors; (c) teacher training and consultation on the use of behavior management techniques within the context of positive relationships with children; and (d) program adoption of evidence-based classroom interventions designed to reduce challenging behaviors in young children that incorporate strategies to enhance teacher-child relationships.