The prevalence of osteoporosis and associated factors were assessed among women 45 years and older as part of the first nationwide German Telephone Health Survey (GSTel03). A total of 14.2% of women reported that a doctor had ever diagnosed them with osteoporosis. Among these about, 15% also reported a physician-diagnosed fragility fracture, the fracture question was restricted to the subgroup of women with osteoporosis. Point estimates of overall osteoporosis prevalence increased significantly across 10-year age bands from 4% in the lowest to 30% in the highest age group. There was no significant association of osteoporosis with socioeconomic status or residence in former East vs West Germany; however, osteoporosis was significantly overrepresented among women with a migration background in comparison to women born in Germany (age-adjusted odds ratio: 1.68; 95% CI: 1.07-2.63). In age-adjusted logistic regression models, osteoporosis was significantly related to physician-diagnosed arthritis or rheumatoid arthritis, significant stature loss (>5 cm) compared to height at age 25 years, postmenopausal hormone therapy, lower ratings of subjective health as well as increased utilization of health care services. No significant association was observed with body mass index computed from self-reported height and weight. In conclusion, despite methodological limitations, these population-based, representative data support the observation that osteoporosis is a prevalent and serious health problem among older women and reflect the considerable variability with regard to diagnosis and management of this condition. Studies evaluating quality of care as well as monitoring of disease endpoints and risk factors based on representative samples of the population are needed.