We report on 6 adopted asymptomatic children in whom chronic HBV infection was identified through the occurrence of an acute hepatitis B in a family member. All of the children had serum HBV-DNA >2000 pg/mL. Acute hepatitis B in a family should alert the physician regarding the possibility of existing chronic HBV infection in other members of the family, especially newly adopted children, leading to a quick evaluation of their HBV status and to an efficacious protection of susceptible family members.