The purpose of this study was to conduct a randomized controlled trial to assess the efficacy of CARES, an online intervention developed to educate undergraduate students about how to communicate in person and over text with friends who experienced the death of someone close to them. College students (N=231) were randomly assigned to one of three conditions: (1) the CARES intervention, (2) a website containing information about grief and loss, or (3) a control condition. Participants completed pre- and post-test quantitative and qualitative measures to assess (1) knowledge of grief, appropriate responses to grieving peers, and resources available for grieving college students, (2) confidence in ability to communicate effectively with grieving peers, and (3) skills in communicating effectively with bereaved friends. The results indicated that students who participated in the CARES intervention had the greatest knowledge regarding grief and appropriate communication with grieving peers when compared to participants in the website and control conditions (when controlling for pre-test scores). In addition, students receiving the intervention were more confident in their ability to help a grieving peer and had the greatest skill in communicating with a grieving peer, when compared to participants in the website and control conditions. No differences were found in knowledge of common signs of grief or knowledge of resources. Thus, the CARES intervention has potential for educating undergraduates about effective communication with their grieving peers.