The aim of the cross-sectional study was to determine if ultrasound (US) measurements of the calcaneus have the ability to predict the risk for fractures and to discriminate between postmenopausal women with and without different types of nontraumatic fractures. All women (n = 1,129, age range 40 to 87 years) were divided into group 1, created by 656 women with 956 nontraumatic past fractures, and group 2, consisting of 473 women without fractures. Group 1 was divided into subgroups: with hip fractures, with vertebral (nonhip) fractures, with wrist (nonhip and nonspine) fractures and with other (nonhip, nonspine and nonwrist) fractures. The speed of sound (SOS; m/s) and broadband ultrasound attenuation (BUA; dB/MHz) were measured with the Achilles system (Lunar), which also calculates stiffness index (SI; %). US values were significantly lower in group 1 (1,481.4 +/- 20.2 m/s, 98.7 +/- 9.4 dB/MHz, 61.1 +/- 11.0%; p < 0.000001) and in subgroups (p < 0.000001), and these women had a higher mean age and longer postmenopausal period than women without fractures (1508.2 +/- 26.5 m/s, 107.7 +/- 9.9 dB/MHz, 74.2 +/- 13.0%). Women with hip fractures had the lowest US values (1464.6 +/- 18.6 m/s, 89.9 +/- 8.7 dB/MHz, 50.6 +/- 10.5%), women with vertebral fractures had intermediate values (1473.6 +/- 17.4 m/s, 94.8 +/- 8.9 dB/MHz, 56.4 +/- 10.0%), and women with wrist (1,484.3 +/- 19.8 m/s, 99.9 +/- 9.3 dB/MHz, 62.7 +/- 10.7%) and other fractures (1,483.3 +/- 21.0 m/s, 100.4 +/- 8.6 dB/MHz, 62.7 +/- 10.6%) had the highest values. The US values differed significantly between subgroups with fractures (p < 0.05), with no significant differences between women with wrist and other fractures. ROC analysis showed SOS to have the best sensitivity and specificity in detecting fracture cases. All US parameters revealed the greatest areas under the ROC curve (AUCs) for hip fracture (0.92 to 0.93) in comparison to smaller AUCs for vertebral fractures (ranging from 0.84 to 0.87), and the smallest AUCs for wrist and other fractures (ranging from 0.72 to 0.77 and 0.72 to 0.78, respectively). Generally, the SOS measurement presented greater odds ratio (OR) than BUA and SI: 4.1 (3.09 to 5.43) for any fracture, 11.66 (3.09 to 43.96) for hip fracture, 6.51 (3.61 to 11.73) for vertebral fracture, 3.32 (2.41 to 4.58) for wrist fracture and 4.2 (2.7 to 6.54) for other fracture. The present study demonstrates the ability of calcaneal QUS to discriminate between healthy individuals and subjects with different types of nontraumatic fractures. Calcaneal US parameters show the best sensitivity and specificity in discriminating the hip fracture patients from the controls. Generally, the SOS parameter is a better discriminator than SI and BUA and estimates the highest OR for fractures.