SummaryBackground and aims. Although several studies have demonstrated a higher incidence of bone disorders in HCV-infected adults, the bone turnover alterations occurring in children and adolescents with chronic hepatitis C has not been thoroughly focused yet. We performed a study on a cohort of 30 HCV infected caucasian children and adolescents to assess the prevalence of osteodystrophy and evaluate a possible prophylactic and therapeutic approach. Methods. Data regarding biochemical markers of bone metabolism were collected. Moreover, results of ultrasonographic bone densitometry yearly performed were evaluated in comparison with data obtained from more than 500 healthy children and adolescents. Results. Osteocalcin and telopeptide of the collagen molecule type-1, CTX, appeared higher than normal in 8/30 and in 7/30 cases respectively; the 25OH vitamin D values were normal in 25/28 cases. By densitometry osteoporosis was detected in 2 patients and osteopenia in other 5. After stratification of cases by age groups, the incidence of osteopenia/osteoporosis appeared higher among children than among adolescents. Osteocalcin levels tended to be higher in cases where hepatic fibrosis were not detected. Conclusions. The higher number of cases of osteopenia/osteoporosis in children than in adolescents is wor-