Osteoporosis is a major public health affects or threatens an estimated 150 million women and men worldwide. Approximately 7% of all women aged 35-40 years and 33% of women older than 65 years have involutional osteoporosis. The World Health Organization define osteoporosis as "a skeletal disorder characterized by compromised bone strength predisposing to an increased risk of fracture." The aim of this study was to assess the elderly knowledge about osteoporosis and to evaluate the impact of educational program on elderly knowledge about osteoporosis. The study was carried out in El-Saada elderly club at Talkha, Mansura district. The study subject comprised 31 elderly visiting El-Saada elderly club regularly. A quasi experimental study was used in the study through evaluating the elderly knowledge about osteoporosis prior to the development of the educational program by using structured interview questionnaire sheet, after implementation of the program the same questionnaire was used to reassess the elderly knowledge immediately after program implementation and after one month of implementation. The results revealed a lack of knowledge which improved in the immediate post test but the knowledge declined after one month in some items. The study recommended that regular educational program should be held to increase their awareness, which helps them to catch the sign of the disease and prevent it. Key words: osteoporosis, elderly knowledge and educational program.