Purpose: This study was conducted to evaluate the effects of an osteoporosis prevention health education on know ledge, health beliefs, self-efficacy and preventive health behaviors of women in an urban area. Methods: A one- group pre-test-post-test design was conducted to identify the effects of an osteoporosis prevention health education. The study was conducted between April and November 2008, and recruited 98 women in Seoul. All participants completed the pretest and posttest measures with self-administered questionaire: Osteoporosis Knowledge Test, Osteoporosis Health Belief Scale, Osteoporosis Self-Efficacy Scale and Osteoporosis Preventive Health Behaviors Survey. Results: The result of the paired t-test revealed statistically significant difference in the perceived susceptibility and perceived benefits of osteoporosis and osteoporosis preventive behaviors between pretest and posttest measures. However, the difference in knowledge and self-efficacy between the pretest and posttest measures was not statistically significant. Conclusions: These finding indicate the need for further health education to increase osteoporosis knowledge, health beliefs, self-efficacy and osteoporosis preventive health behaviors and provide guidance for developing effective osteoporosis prevention health education strategies.