Sexual health text message services are becoming increasingly popular, but little is known about who uses such services and why. This project details the implementation of a campaign promoting a state-wide sexual health text message service that allows teens to text directly with a health educator and uses a mixed method design to assess who uses the service, what motivates use, and potential barriers to using the service. A theory of information seeking through text messaging is posited based on previous information seeking and communication theory and tested with adolescents. A social marketing campaign was created promoting a North Carolina sexual health text message service and conducted in six middle and high schools in the North Carolina Piedmont region in Fall 2012. More than 2000 students in four schools completed online questionnaires that assessed awareness of the service, perceptions, and use. Focus groups and in depth interviews were then conducted with middle and high school students. Results indicate teens who are sexually active and in relationships are more likely to use the service. A teens' level of uncertainty about sexual health influences affect, which in turn leads adolescents to assess various information options. Positive attitudes toward the service and credibility perceptions are direct predictors of intentions to use. Efficacy was found to be an indirect predictor, working through credibility perceptions to influence intentions to use. Although teens may have an interest in using the service, there are barriers associated with use. Survey findings and qualitative results indicate that teens are interested in using a sexual health text message service, but perceived costs, fear of parents finding out about service use, and a lack of understanding of how to use the service were barriers for some teens. This study has implications for sexual health text message services, especially those that allow teens to connect directly with a health educator. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]