Historically, the political context of partner physical aggression policy and research has focused on protection of physically victimized women and mandated interventions for male batterers. This emphasis is understandable when one considers the injuries and deaths of women by men. However, physical aggression against partners among teens is a very different phenomenon than battering. Intimate partner violence (IPV) in the form of physical aggression, the focus of this review, often starts in junior high school, and approximately 35% of male and female senior high school students report engaging in IPV. The specific trajectory of IPV varies by sample, but IPV appears to decrease in the late teens or early 20s. IPV is generally reported by both males and females, and not attributable to self-defense. IPV is significantly stable in couples who remain together, but stability appears lower if partners change. Given the importance of physical aggression by both males and females, prevention and early intervention programs need to address relationship factors, and targeted prevention and early intervention would be prudent with young high-risk couples. Decades of intervention programs for batterers have not proven very successful, and IPV appears easier to prevent than treat. Thus, emphasis on prevention of IPV seems both timely and promising. This review is intended for diverse audiences including educational administrators, policy makers, and researchers. It reviews issues such as who and when to target for IPV prevention programs, and it summarizes data relevant to these issues.