The optimal method to assess pediatric bone mass remains controversial. Dual x-ray absorptiometry (DXA) is commonly used but quantitative ultrasound is less expensive, free of ionizing radiation, and predicts fractures as well as DXA does, in adults. Broadband ultrasound attenuation (BUA) was determined using a portable calcaneal ultrasonometer and, compared with DXA derived areal bone mineral density (BMD) values in 42 young patients (ages 4.5 to 20.3 y) with leukemia. Reduced BMD was defined as a DXA z score of <-1. Mean z scores for lumbar spine BMD were significantly lower than zero (-0.77+/-1.23 SD, P=0.0004). Mean z scores for whole body BMD were also significantly lower than different from 0 (-0.34+/-1.04 SD, P=0.05). Calcaneal BUA was highly correlated with DXA measurement of lumbar, whole body, and femoral neck BMD. BUA was significantly associated with the probability of having a reduced lumbar BMD z score (P=0.03) and having a reduced whole body z score of (P=0.03). Area under the receiver operator characteristic curves for model including BUA predicting reduced bone density by DXA were 0.77 and 0.86 for lumbar and whole body z score cutoffs, respectively. Our data suggest that calcaneal BUA may serve as a reliable screening tool to detect reduced bone mass in pediatric patients with leukemia.