Little attention has been paid to goal structures in health education, despite their well-established roles in motivation and learning. The primary goal of this study was to examine the longitudinal relations of classroom goal structures to high school students' (N = 636) motivation and learning outcomes in health education. We incorporated two aspects of motivation: self-efficacy for negotiating condom use and task values for learning new information about HIV and pregnancy prevention. Results revealed that students' perceptions of a mastery goal structure were positively related to their self-efficacy and task values, and also their knowledge and behavioral intentions one year after the health education curriculum had been delivered. In contrast, students' perceptions of an extrinsic goal structure were not related to their motivation and learning outcomes. Our findings suggest that the implementation of instructional practices focusing on mastery may enhance the efficacy of HIV and pregnancy prevention programs.