OBJECTIVES: The objectives of this study were to estimate the prevalence of hepatitis B virus protection, infection, and recovery among internationally adopted children and to examine the need for repeat testing 6 months after arrival in the United States. METHODS: From November 1999 through October 2006, 1282 international adoptees were screened for hepatitis B virus, and results were examined with regard to age, gender, and birth country. The prevalence of hepatitis B virus protection, infection, and recovery was determined. RESULTS: The prevalence of hepatitis B virus in internationally adopted children at our large international adoption center was 4%, including 1.1% with acute or chronic infection and 2.9% with resolved infection. Overall, 64% of internationally adopted children had evidence of hepatitis B virus immunization, with protective antibodies. We also report a case that highlights the need for repeat serological testing to detect hepatitis B virus infection or immunization in internationally adopted children who might have been infected or vaccinated just before adoption and thus not have serological evidence in initial testing. CONCLUSIONS: These data reinforce the American Academy of Pediatrics recommendations regarding hepatitis B virus screening and infection control measures for international adoptees.