Osteoporosis is a "pediatric disease with geriatric consequences." This article describes the development and pilot testing of an online system to educate high school students grades 9-12 about osteoporosis; an age where positive health changes could have long lasting effects. The intervention goal was to improve knowledge about osteoporosis and intent to adopt healthy bone practices. Online pre- and postintervention surveys evaluated participants' pre- and postintervention osteoporosis knowledge, attitudes, preventive practices, and postintervention intent to change healthy bone practices. Participants completed the Web-based program that provided detailed information about osteoporosis, and healthy bone practices, immediately after completing the pretest and just prior to completing the posttest. Eighty-nine students completed both the pre/posttests and were included in data analysis. Participants ranged in age from 13 to 17 and 75% were Caucasian (n = 65). Based on pre/posttest scores of 9 factual questions, students significantly improved their knowledge (p < .0001) and overall knowledge rating about osteoporosis at posttest (p < .001). Participants changed their perception regarding the disease's seriousness (p < .001), and considered adopting osteoporosis prevention practices. The study shows that an interactive educational Web site is an effective method for increasing awareness and understanding of osteoporosis in high school students.