Calibration of the Finnish FRAX model was evaluated using a locally derived population-based cohort of postmenopausal women (n = 13,917). Hip fractures were observed from national register-based data and verified from radiological records. For a subpopulation of 11,182 women, there were enough data to calculate the fracture probabilities using the Finnish FRAX tool (without bone mineral density). A 10-year period prevalence of hip fractures to this subpopulation was 0.66 %. The expected numbers of hip fractures were significantly higher than the self reported ones (O/E ratio 0.46; 95 % CI 0.33-0.63), had a tendency to be greater than the observed ones (O/E ratio 0.83; 95 % CI 0.65-1.04), and calibration in terms of goodness-of-fit of absolute probabilities was questionable (P = 0.015). Strikingly, the 10-year period prevalence of hip fractures to the whole cohort was higher (0.84 %) than for the women with FRAX measurements (0.66 %). This was mainly the result of difference between people who had and who had not responded to postal enquiries (0.71 vs. 1.77 %, P