Around the world, there are growing efforts to involve boys and men in the prevention of violence against women: as participants in education programs, as targets of social marketing campaigns, as policy makers and gatekeepers, and as activists and advocates. Efforts to prevent violence against girls and women now increasingly take as given that they must engage men. While there are dangers in doing so, there also is a powerful feminist rationale for such work. This article provides a review of the variety of initiatives which engage or address men in order to prevent violence against women. It maps such efforts, locating them within a spectrum of prevention activities. Furthermore, the article identifies or advocates effective strategies in work with men to end violence against women.