We evaluated ultrasound propagation through the calcaneus using the Achilles Lunar unit in patients with postmenopausal or glucocorticoid-induced osteoporosis. Speed of sound, broadband ultrasound attenuation and a combination of these two parameters called stiffness were determined. Reproducibility was 0.23%, 2.6%, and 2.6% for these three parameters, respectively. Bone mineral density measured at the spine and femoral neck by absorptiometry was significantly correlated with all three ultrasound parameters in the women with postmenopausal osteoporosis (n = 47) and in the controls (n = 42). In the patients with glucocorticoid-induced osteoporosis (n = 35), only speed of sound was significantly correlated with the bone mineral density measurements. Mean values in the subjects with postmenopausal osteoporosis and in their age-matched controls were 1473 +/- 27.2 m/sec versus 1500.6 +/- 29.6 m/sec for speed of sound, 95.3 +/- 9.6 dB/Mhz versus 105.7 +/- 10.1 dB/Mhz for broadband ultrasound attenuation, and 56.1 +/- 13.2 versus 70.9 +/- 14.1 for stiffness, indicating a significant difference (P < 0.01). Z scores were -0.91, -1.1, -0.93, -0.97, and -1.05 for bone mineral density at the spine, bone mineral density at the femoral neck, speed of sound, broadband ultrasound attenuation and stiffness, respectively. Receiver Operating Characteristic curves showed that there were no statistically significant differences between the ultrasound parameters at the calcaneus and the absorptiometry measurements at the spine and femoral neck. Mean values in glucocorticoid-treated patients and age-matched controls were 1480 +/- 26.9 m/sec versus 1505.1 +/- 30.3 m/sec for speed of sound, 99.2/-11.4 dB/Mhz versus 105.9 +/- -10.2 dB/Mhz for broadband ultrasound attenuation, and 60.7 +/- 14 versus 72.1/14.5 for stiffness, again indicating a significant difference (P < or = 0.01). Z scores were -0.55, -0.65, -0.8, -0.67, and -0.78 for bone mineral density at the spine, bone mineral density at the femoral neck, speed of sound, broadband ultrasound attenuation and stiffness, respectively. Our data suggest that ultrasound parameters measured at the calcaneus are useful for evaluating postmenopausal and glucocorticoid-induced osteoporosis.