Objectives. – Quantitative ultrasound (QUS) has emerged as a new tool in the assessment of fracture risk. The aim of this study was to compare the clinical utility of QUS parameters measured using imaging and non-imaging devices in the discrimination of osteoporotic patients. Methods. – QUS (Broadband Ultrasound Attenuation, BUA dB/MHz, and Speed of Sound, SOS m/s) were measured and then statistical analyses were performed. Results. – The 106 women included were 65 ± 8 years aged. Using DXA, T score was ≤–2.5 at either lumbar spine or hip in 59% of patients, and 25% had osteoporotic fractures. QUS results were different among devices, and these differences were highly dependent on the measured value. There was a similar effect of age and duration of menopause for all parameters. To obtain 90% of sensitivity for the diagnosis of osteoporosis, the thresholds were 50.80 and 71.70 dB/MHz for BUA and 1544.80 and 1551.50 m/s for SOS, using imaging and non-imaging devices, respectively. Belonging to the highest tertile of QUS had a negative predictive value for osteoporosis ranging from 59% to 65%. In the lowest tertile of QUS, the proportion of osteoporotic women was between 73% and 80%. All QUS parameters, except BUA measured with the non-imaging device, were able to discriminate post-menopausal women with fractures after adjustment for age and hip BMD. Conclusions. – Our data suggest that an imaging system improves the utility of BUA measurement, but not SOS, for post-menopausal osteoporosis assessment.