Background: Osteoporosis is an emerging geriatric condition with high morbidity and healthcare cost in developing nations, characterized by low bone mass, which increases bone fractures among elderly females. Aim: Evaluate the effect of health educational program on the self- efficacy of elderly females regarding osteoporosis. Design: A quasiexperimental research design was done on a convenience sample of, 30 elderly females from El-Amal elderly club at Mansoura city. Tools: Four tools were used; Demographic Data Interview Form, Osteoporosis Knowledge Tool, Osteoporosis Health Belief Scale, and Osteoporosis Self-Efficacy Scale. Results: Post-intervention, the overall knowledge score, benefits of exercise and Calcium intake, health motivation and perceived susceptibility and seriousness to osteoporosis, were improved significantly (P≤0.001) among the elderly females compared to preintervention ones. Also, perceptions of exercise and calcium intake barriers were decreased significantly (P≤0.001) post intervention compared to pre- intervention. Moreover, osteoporosis self-efficacy scale improved significantly (P≤0.001) post-intervention compared to pre- intervention. Conclusion: The health educational program based on health belief model is effective in improving the elderly females' knowledge regarding osteoporosis, health beliefs and osteoporosis self-efficacy. Recommendations: In future studies, more extensive interventions on the structures of calcium intake benefits and barriers, as well as other behavioral modification theories, should be used.