Men who have sex with men (MSM) frequently use Internet-based Web sites to recruit sex partners. Although many MSM users of such sites advocate for safe sex practices in their personal profiles, some users actively recruit sexual partners who wish to participate in anal sexual intercourse without the use of condoms, also known as "bareback" sex. Participating in this sexual practice places both sexual partners at higher risk of HIV transmission. In addition, data indicate this behavior is associated with other high-risk activities such as drug use and communication of other sexually transmitted infections. This article summarizes the literature assessing this phenomenon on the Internet. Specific recommendations are provided for clinicians, health educators, and researchers.