Objective: Because of its high prevalence and serious consequences for victims, sexual violence is a significant problem on college campuses. Sexual assault prevention programs based on the bystander intervention model have been shown to be effective; however, current programs are limited in terms of ease of distribution. To address this issue, we developed and evaluated “Take Care,” an online bystander intervention program. To our knowledge, this is the first empirical evaluation of an online bystander intervention program designed to prevent sexual violence. Method: Ninety-three participants (80.6% female, 19.4% male) recruited from social psychology classes at a midsize university were randomly assigned to view 1 of 2 online programs: Take Care or a control program on study skills. Before viewing the programs, participants completed measures of bystander behaviors and feelings of efficacy for performing such behaviors. Measures were administered again postintervention and at a 2-month follow-up assessment. Results: Participants who viewed Take Care reported greater efficacy for engaging in bystander behaviors at postintervention and 2 months after treatment, compared with those who viewed the control program. In addition, participants who viewed Take Care reported performing relatively more bystander behaviors for friends at the 2-month follow-up assessment, compared with participants who viewed the control program. Conclusions: These results suggest that sexual violence prevention programs may be effectively adapted to an online format. (PsycINFO Database Record (c) 2015 APA, all rights reserved)