Bystander intervention is receiving increased attention as a potential sexual violence prevention strategy, especially to address campus sexual assault. Rather than focusing on potential perpetrators or victims, the bystander approach engages all members of a community to take action. A growing body of evaluative work demonstrates that bystander intervention education programs yield increased positive attitudes and behaviors related to sexual violence and greater willingness to intervene in pro-social ways. Future program outcome studies, however, would benefit from more refined measures of bystander action as it is a key variable that prevention education programs attempt to influence. The purpose of the current article is to present key issues, identified by four different research teams, on the measurement of bystander behavior related to sexual violence in the context of college campuses. Comparisons among the methods are made to suggest both lessons learned and new directions for bystander behavior measurement using self-report surveys in program evaluation.