Hypoxemia has been associated with low bone mineral density (BMD) in animal and human models. We assessed the association of haemoglobin levels with ultrasound-derived (UD) T score, Z score and the stiffness index in all 358 subjects aged 75+ living in Tuscania (Italy). Also, we searched for the haemoglobin cutoff levels that might best identify participants with osteoporosis. In the multivariable linear regression analysis, haemoglobin levels were associated among participants with the UD T score [β = 0.13; 95% confidence interval (CI) = 0.01-0.25; p = 0.030], Z score (β = 0.11; 95% CI = 0.01-0.22; p = 0.045) and stiffness index (β = 1.87; 95% CI = 0.51-3.21; p = 0.007) after adjusting for potential confounders. Haemoglobin levels <140 g/L in men and <130 g/L in women best predicted osteoporosis in linear discriminant analysis. Haemoglobin is independently associated with all UD-BMD parameters. Haemoglobin levels <140 g/L in men and 130 g/L in women might be adopted in clinical practice to identify older subjects in whom screening for osteoporosis might yield higher effectiveness. © Clinical Rheumatology 2008.