Background: Osteoarthritis (OA) is among the most prevalent musculoskeletal disorders and devastating diseases and is the fourth contributing cause of disability in the world. Also, it carries excess mortality as well as financial encumbrance both on societal level and to women inflected with it. Aim: assess the effect of applying health belief model on osteoarthritis preventive behaviors among women in their middle age. Subjects and Method: Design: quasi-experimental research design with one group pre/post-test approach. Setting: at five primary health care centers within the city of Port Said. Subjects: purposive sample of 147 women attending the five mentioned setting. Tools: the tools used were counted as three: Tool I: Women's Assessment Questionnaire about Osteoarthritis Prevention. Tool II: The Osteoarthritis Health Belief Model (HBM) Scale. Tool III: Osteoarthritis Preventive Behaviors. Results: pre-program intervention (89.1%) had an unsatisfactory level of knowledge while only (11.6%) post program intervention. (94.6%) of study women had a low level of preventive behaviors pre-program intervention compared to (24.5%) post program intervention. Conclusion: The study concluded that a statistically significant enhancement was evident between the health belief model scale category before and after program intervention (p =0.001). In addition to that, a highly statistically significant difference present between total knowledge, osteoarthritis health belief model & level of preventive behaviors regarding osteoarthritis before and after program intervention (p=0.001). Recommendations: The continuing education program is needed about osteoarthritis that is directed to women to raise awareness. Long-term follow-up (3 months after the intervention) to investigate the intervention's impact on the continuation of behavior.