This work has undergone a double-blind review by a minimum of two faculty members from institutions of higher learning from around the world. The faculty reviewers have expertise in disciplines closely related to those represented by this work. If possible, the work was also reviewed by undergraduates in collaboration with the faculty reviewers. AbstractFraternity and sorority members are overrepresented as perpetrators and victims of sexual assault, respectively. The current study examined rape myth acceptance, bystander attitudes, and bystander efficacy across four groups: sorority women, fraternity men, non-affiliated women, and non-affiliated men. Data were collected from 912 college undergraduates. Greek affiliated students were more accepting of rape myths than non-affiliated students. There were no differences in bystander attitudes based on Greek affiliation; however, Greek affiliated students did report significantly lower bystander efficacy than non-affiliated students. Sorority women and fraternity men reported no differences in their acceptance of rape myths or bystander efficacy; however, sorority women did report higher bystander attitudes than fraternity men. Based on the findings, it is recommended that prevention practitioners work to change norms within fraternities and sororities to promote a social identity that is associated with gender equality and a willingness, perhaps even an obligation, to intervene in risky situations.