The Bindex(®) quantitative ultrasound (QUS) device is currently available and this study analyzed (I) its relative and absolute intra- and inter-session reliability and (II) the relationship between the data provided by Bindex(®)-QUS and the bone mineral density (BMD) measured by dual-energy x-ray absorptiometry at corresponding skeletal sites in young and healthy subjects (age: 25.0 ± 3.6 years). Bindex(®)-QUS calculates a density index on the basis of the thickness of cortical bone measured at the distal radius and the distal plus proximal tibia. The data show a very good relative and absolute intra- (ICC = 0.977, CV = 1.5%) and inter-session reliability (ICC = 0.978, CV = 1.4%) for the density index. The highest positive correlations were found between cortical thickness and BMD for the distal radius and distal tibia (r ⩾ 0.71, p < 0.001). The data indicate that the Bindex(®)-QUS parameters are repeatable within and between measurement sessions. Furthermore, the measurements reflect the BMD at specific skeletal sites. Bindex(®)-QUS might be a useful tool for the measurement of skeletal adaptations.