Adolescent sexually transmitted infection (STI) and birth rates indicate a need for effective middle school HIV/STI, and pregnancy prevention curricula to delay, or mitigate consequences of, early sexual activity. Individual and organizational barriers to adoption, implementation, and maintenance, however, can hamper dissemination of evidence-based sexual health curricula, adversely impacting fidelity and reach. Internet-based approaches may help mitigate these barriers. This paper describes the development and feasibility testing of It’s Your Game (IYG)-Tech, a stand-alone 13-lesson Internet-based sexual health life-skills curriculum adapted from an existing effective sexual health curriculum—It’s Your Game… Keep it Real (IYG). IYG-Tech development adaptation steps were to: 1) Select a suitable effective program and gather the original program materials; 2) Develop “proof of concept” lessons and test usability and impact; 3) Develop the program design document describing the core content, scope, and methods and strategies; and 4) produce the new program. Lab- and school-based tests with middle school students demonstrated high ratings on usability parameters and immediate impact on selected psychosocial factors related to sexual behavior—perceptions of friends’ beliefs, reasons for not having sex, condom use self-efficacy, abstinence intentions, negotiating with others to protect personal rules, and improved knowledge about what constitutes healthy relationships (all p < .05). Youth rated IYG-Tech is favorably compared to other learning channels (>76.2% agreement) and rated the lessons as helpful in making healthy choices, selecting personal rules, detecting challenges to those rules, and protecting personal rules through negotiation and refusal skills (89.5% - 100%). Further efficacy testing is indicated for IYG-Tech as a potential strategy to deliver effective HIV/STI, and pregnancy prevention to middle school youth.