Purpose: The purpose of this study was to evaluate the effectiveness of a theory-based computer-tailored osteoporosis prevention program on calcium and vitamin D intake and osteoporosis health beliefs in young women. Additionally, this study tested whether adding bone density testing to the intervention improved the outcomes. Methods: One hundred (n = 100) women aged 19 to 25 years were randomly assigned to one of 2 groups. One group (n = 50) received the computer-tailored program with brief counseling and the second group (n = 50) received the same intervention plus bone density testing of the heel (quantitative ultrasound [QUS]) feedback. Results: Participants within both groups statistically significantly increased calcium and vitamin D intake from baseline to 1 month after the interventions. Both groups also experienced statistically significant decreases in perceived barriers to obtaining adequate vitamin D intake. Discussion: The theory-based computer-tailored osteoporosis prevention program resulted in significant improvements in osteoporosis beliefs and calcium and vitamin D intakes. The bone density test did not improve results. Translation to Health Education Practice: Though future research is needed, this preliminary study holds promise for health education practice to use theory to plan osteoprotective computer programs for young women.