The HIV/AIDS epidemic continues to pose a severe health threat to young Americans. The popularity of using social networking websites (SNSs) has grown considerably over the past few years, and they offer an opportunity to reach people with HIV prevention messages. Receptivity to messages about HIV delivered through SNSs has not been assessed to our knowledge. Our study explored users’ receptivity to receiving information about HIV through the SNSs they use. We first assessed whether respondents currently use the Internet to look for information about HIV. Next, we presented several hypothetical scenarios about how they may obtain information about HIV through an SNS and gauged their reactions to each scenario. About one-quarter of respondents were receptive to receiving information about HIV via an SNS. Forty-one percent would open a message about HIV from a person or organization on their friends list, 21% would open a message about HIV if the source was not on their friends list, and 60% were interested in completing a personal risk assessment for HIV online via an SNS. The rapid growth of SNSs presents a significant opportunity to reach individuals with HIV prevention messages, but these efforts need to be evaluated to assess effectiveness.