Our objective was to investigate hepatitis C virus (HCV) seroprevalence in homeless caregivers and their children 2-18 years of age living in a family. During a 30-month period from October 2001 through April 2004 in Baltimore, 170 caregivers enrolled and 168 of these accepted testing for antibody to HCV (anti-HCV), as did all 336 children and adolescents enrolled. Main results. None of the children younger than 18 years old were HCV seropositive; in striking contrast, however, 32 (19%) caregivers were seropositive. Most (59%) were previously unaware of their HCV serostatus. History of ever injecting drugs was the strongest predictor of HCV seropositive status in the caregivers, reported by 14% overall, and by 71% of HCV positives. Conclusion. The homeless families were very receptive to our HCV seroprevalence study and are likely also to be receptive to shelter-based HCV prevention programs for young children and adolescents as well as for adults.