Quantitative ultrasound (QUS) is of increasing interest for evaluation of osteoporosis because, compared with dual-energy X-ray absorptiometry (DXA), it is portable, less expensive, and radiation-free. The aim of our study was to determine the sensitivity, specificity, and cut-off values of quantitative ultrasound parameters in identifying patients with osteoporosis compared to the World Health Organization (WHO) standard definition. We performed a cross-sectional investigational study of 73 subjects, and determined total hip and lumbar spine T-scores by dual-energy X-ray absorptiometry (DXA) (Prodigy Advance Lunar-GE). The QUS parameters (broadband ultrasound attenuation [BUA], speed of sound, bone mineral density, the stiffness index, and QUS T-score) were determined with Sahara Hologic equipment. The AUC was 0.81 (95% CI 0.67–0.95, p<0.05) for speed of sound (SOS) and 0.76 (95% CI 0.62–0.90, p<0.05) for BUA for the patients with DXA T-scores ≥ −1 DS; the cut-off values were 1542.2 meters per second for SOS and 63.3 dB/MHz for BUA. In patients with DXA T-scores ≤ − 2.5 DS, AUC was 0.80 (95% CI 0.70–0.90, p<0.05) for SOS, and 0.76 (95% CI 0.65–0.87, p<0.05) for BUA. The cut-off values were 1504.95 meters per second for SOS and 49.5 dB/MHz for BUA. Pearson correlation coefficients were positive and statistically significant (> 50%) for all QUS parameters in both groups, (2-tailed, p<0.05). QUS parameters correctly identified normal patients (false negative 34.21% and false positive 2.53%) and those with osteoporosis (false negative 8.55% and false positive 7.82%). The patients with QUS parameters between the cut-off values corresponding to DXA T-scores of −1 SD and − 2.5 SD should be further evaluated by DXA.