Purpose: The purpose of this study was to evaluate the effectiveness of theory-based osteoporosis prevention programs on calcium and vitamin D intakes and osteoporosis health beliefs in young women. Methods: Women (N = 152) aged 19 to 25 years were randomly assigned to one of 3 groups: a brochure group (n = 51), a computer-tailored program group (n = 51, and the same computer-tailored program (n = 50) with brief verbal feedback. Participants completed surveys regarding osteoporosis beliefs prior to and immediately after assigned intervention. They also completed surveys measuring osteoporosis behaviors before and 1 month after intervention. Results: Participants (n = 152) in all groups significantly improved calcium intakes from baseline to 1 month after interventions. All groups experienced significant decreases in perceived barriers to obtaining adequate vitamin D and significant increases in perceived osteoporosis susceptibility and severity. Discussion: Interventions that delivered osteoporosis material via a brochure or tailored computerized messages with or without brief feedback from a health professional were successful. These changes may be due to theory-based components of the interventions. Translation to Health Education Practice: Though future research is needed, this study holds promise for health education practice to use health behavior theory to plan cost-effective osteoprotective programs for young women.