Beginning with a reader-friendly review of the literature, Cynthia Hudley underscores the substantial risks of long-term problems for elementary-school-age children who demonstrate aggressive behavior. Then, drawing on her work as founder of a successful school intervention program, the BrainPower Program, Hudley describes methods for reducing children’s peer-directed aggression. She concludes with a discussion of the importance of broad social contexts in supporting nonaggressive behavior.