Appropriate supportive care and identification of long-term sequels of therapy are of paramount importance in HIV-infected pediatric patients. As low bone mineral quality (BMQ) in patients can be considered a marker of possible degeneration in osteopenia and osteoporosis in adulthood, we evaluated bone features in a pediatric population. Forty-four patients (23 females, 21 males; aged 3-17 years) were compared with a control population (1227 healthy children: 568 females, 641 males; aged 3-18 years). Seven patients were CDC stage C, 18 B, and 18 A. All patients were vertically infected; four were naive to any antiretroviral treatment, seven were taking two NRTIs, and 32 were on HAART. BMQ was assessed by a quantitative ultrasound (QUS) technique. It measures the amplitude-dependent speed of sound (AD-SoS, m/sec) and the bone transmission time (BTT, microsec). QUS values were significantly lower in cases than in controls, even after adjustment for age and body size (AD-SoS: 1924.7 +/- 64.9 and BTT: 0.97 +/- 0.3 in controls; AD-SoS: 1879.7 +/- 57.2 and BTT: 0.80 +/- 0.32 in cases; p < or = 0.001). The associations of AD-SoS and BTT with gender, type of therapy, and CDC stages were not significant. AD-SoS and BTT were significantly associated with age (r = 0.59, p < 0.0001), skeletal age SDS (r = 0.46, p = 0.002), height (r = 0.66, p < 0.0001), and therapy duration (r = 0.31, p = 0.04). Both AD-SoS and BTT values in patients fell below mean values of controls. Follow-up of bone mineral density is important in patients to prevent long-term problems of skeletal status.