According to the recent recommendations of the European Community and the World Health Organization, identification of risk factors for fracture or low bone mineral density (BMD) should help health professionals to make a better use of bone densitometry. This includes helping patients to modify their behaviour and act on modifiable risk factors (correction of low calcium intake and vitamin D deficiencies, etc.) and also to provide evidence-based guidance for starting a treatment when necessary. In this context, we previously developed a clinical scoring index, OSIRIS (OSteoporosis Index of RISk), for classifying women into three categories of risk of osteoporosis. In order to evaluate the discriminatory performance of OSIRIS, we performed the present prospective study in a sample of 889 postmenopausal women from France. The osteoporosis risk depends on the OSIRIS category. Thus, 62% of women in the 'high-risk' category (OSIRIS < or = -3) were osteoporotic, compared to 34% of women in the 'intermediate-risk' category (OSIRIS ranged between -3 and +1) and only 16.8% of women in the 'low-risk' category (score OSIRIS > 1). These results might contribute to the development of more efficient screening strategies for osteoporosis. The patients in the low-risk category do not require immediate BMD testing; women with 'intermediate risk' have to be carefully followed by their doctor with BMD testing decided on a case-by-case basis; for those within the high-risk category, treatment may be initiated immediately and BMD testing performed either to assess the efficacy of the treatment or to increase the long-term compliance of the patient. In conclusion, for clinical practice, a user-friendly tool has been developed. This tool, called OSIRIS, as far as a simple rule allows, identifies the level of osteoporosis risk in women.