Research Findings: Pretend play is an essential part of child development and adjustment. However, parents, teachers, and researchers debate the function of aggression in pretend play. Different models of aggression predict that the expression of aggression in play could either increase or decrease actual aggressive behavior. The current study examined pretend play and classroom behavior in preschoolers. Children ("N" = 59) were administered a measure of pretend play, and teacher ratings of classroom behavior were obtained. Pretend play skills were positively associated with prosocial behavior in the classroom and negatively associated with physical aggression in the classroom. In particular, expression of oral aggression in play related to less physical aggression and more prosocial behavior in the classroom. Practice or Policy: These findings suggest that pretend play should be encouraged, as these skills relate to positive behaviors in the classroom. In addition, it was found that aggression in pretend play was not an indicator of actual aggressive behavior, as it related to positive behaviors in the classroom. Implications for parents and teachers are discussed. (Contains 2 tables.)