Bone mineral density (BMD) is used as a clinical estimate of the risk of fracture. Ultrasound provides an alternative or complement to X-ray based methods of bone densitometry for determining BMD. Among ultrasonic characteristics, the speed of sound (SOS) is a useful tool for assessment of osteoporosis because, as recently reported, it represents a combination of density and compressibility of bone tissue. Thus, it might provide better information on bone quality to estimate the fracture risk. In this paper, a dual-transducer ultrasound technique was employed to measure the mean ultrasound propagation speed of the cortical layer as well as the cancellous layer at the tibia shaft. Encouraging results from 18 outpatients showed a high correlation (r = 0.93) between measurements of BMD and those from dual energy X-ray absorptiometry (DEXA).