This study examined the effectiveness of Safe Sisters, a sexual assault bystander intervention program that targets members of college sororities. Analysis of covariance results show significant differences between treatment and waitlist control groups on posttest scores for action, bystander efficacy, intent to help friends, and intent to help strangers. Significant differences are not shown between treatment and waitlist control groups on posttest scores for precontemplation, contemplation, and rape myth acceptance. Limitations and implications are discussed.