Osteoporosis is one of major problems and is a common debilitating metabolic disease among women. Young women need to be aware of the risk factors and the proper preventive behaviors of osteoporosis to prevent its complications and subsequent effects. Purpose: To investigate the effect of an educational intervention based on Pender health promotion model on osteoporosis preventive behaviors among employed women. Design: Quasi-experimental design was used. Setting: five of ten non medical faculties affiliated to Menoufia University were chosen by multistage random selection. Sample: A convenience sample of 100 premenopausal an employed woman was selected from. Instruments: Self-administered questionnaire was utilized which included two main parts: the first part was socio-demographic characteristics; the second part was studied women's knowledge and Pender health promotion model variables regarding osteoporosis prevention. Results: a statistically significant difference between pre-post intervention regarding to the total knowledge score about defining osteoporosis and its related risk factors 17 ± 5.2  in posttest compared to 6± 6.6 in pre-test. A statistical significant improvement showed in the concepts of Pender health promotion in posttest comparable with pretest. Conclusion: educational intervention based on Pender health promotion model had significant effect on premenopausal employed women's knowledge and preventive behaviors of osteoporosis including; perceived benefits, barriers, self-efficacy, activity related-affect, interpersonal and situational influences. Recommendations: Health education based on Pender health promotion model for promoting osteoporosis preventive behaviors should be provided.