OBJECTIVE: To develop an epidemiological model of osteoporosis and its sequelae to estimate the current and future prevalence of osteoporotic fractures in females aged 45 years and over, in different European countries. METHODS: A decision-analytic model employing a Markov process was constructed using MS Excel. Country-specific population projection figures were combined with data from major European epidemiological studies to estimate the current and future prevalence of osteoporotic fractures in women. Regional prevalence data came from the European Vertebral Osteoporosis Study (EVOS) and incidence data from the follow-up European Prospective Osteoporosis Study (EPOS). Results for France, Germany (Western Europe), Italy, Spain (Southern Europe), Sweden, and Finland (Scandinavia) will be presented. RESULTS: A total of 1.8 million osteoporotic fractures are estimated to occur in women aged 45 years and older in these 6 countries in 2003. Vertebral fractures are the most common type, accounting for almost 1.1 million of all fractures. It is also estimated there will be almost 250,000 wrist fractures, 220,000 hip fractures and 290,000 'other' fractures. The overall rates of fractures are substantially higher for the Scandinavian countries than for the other countries: France 28.2/1000, Germany 28.4/1000, Italy 28.8/1000, Spain 31.0/1000, Finland 61.9/1000, and Sweden 71.0/1000 women. CONCLUSIONS: Osteoporotic fractures are an important cause of morbidity in these countries. Vertebral fractures are the most common type, thus warranting study of their economic and health impact. The variations in rate of fracture between regions reflect predominantly the differing prevalence and incidence rates found in the EVOS and EPOS studies, and to a lesser extent, the country-specific age structures.