Background. It is commonly known that the main characteristic feature of osteoporosis is bone brittleness, whose complications include fractures. Consequently the most important treatment objective is to prevent fractures by maintaining or increasing bone mass, to prevent falls and injuries, to reduce acute and chronic conditions and to improve physical, and psychosocial functions. The significance of increased physical activity as one of the protective factors that prevent bone fractures in an elderly age needs to be underscored. Osteoporosis becomes a not only a medical challenge, but also a social and economic problem. Such a dynamically growing problem is the reason behind the present paper whose aim is to show if and to what extent selected factors, such as age, body mass and physical activity influence bone mineral density (BMD) in post-menopausal women. Material and methods. 54 women participated in the study, median age 66.8 years. Bone mineral density was determined on the basis of a densitometric test, which was then juxtaposed with osteoporosis risk factors and correlations were analysed. On the basis of body mass and height of study participants the body mass index was calculated (BMI). Data concerning physical activity over the last dozen years or so was obtained during an interview. The level of physical activity was assessed using a four-grade scale developed by the author. Results. A statistically significant negative correlation was shown between BMD and the age of women participating in the study (p<0,01). A similar correlation was observed (p<0,01) between (BMD) an the BMI. A very high correlation (p<0,001) was shown between BMD and physical activity of women participating in the study. Conclusions. An important factor in osteoporosis prevention is physical activity. Age is not necessarily a risk factor in osteoporosis. Moderate overweight has a positive impact on BMD level.