Sexual health text message services are becoming an increasingly popular way to reach young people with sexual health information. A variety of service types exist: some send automated messages on a set schedule; others provide personalized responses to individual questions. Young people’s perceptions of interactivity, which is often based on system responsiveness, may vary. This study examines perceptions of interactivity for users of a two-way text message service that connects young people directly with a health educator and examines the relationship between perceived interactivity and attitudes toward the service, service satisfaction, and repeated service use. Data from 131 users in the southeastern U.S.A. were analysed. Perceived interactivity was associated with positive attitudes, user satisfaction and repeat use. Data suggest that for sexual health information seeking, young people may view a program as more useful if they perceive it is interactive. Services that provide a back-and-forth dialog between health educators and users may be perceived as interactive, and those perceptions of interactivity can influence attitudes toward the service as well as behaviors, such as using the service repeatedly. Since such services offer accurate and timely health information, repeated use allows for the additional exchange of health information and educational opportunities.