SUMMARYThe aim of the study was to describe the epidemiology and determinants of anti-hepatitis A seroprevalence in 2- to 19-year-olds in the USA for 2007–2008. This study was conducted in a sample of 2621 individuals aged 2–19 years in the USA using data from National Health and Nutrition Examination Survey (NHANES) 2007–2008. The overall seroprevalence of anti- hepatitis A virus (HAV) in this population was 39% (95% confidence interval 32·6–45·3). HAV seroprevalence was higher in Mexican Americans than other ethnic groups, in younger persons, and in those who reported previous vaccination compared to those who did not. We concluded that anti-hepatitis A seroprevalence rates are increasing in younger individuals in the USA, indicating a shift of seroprevalence over time due to vaccination status. Findings are consistent with a persistent influx of infection through international travel and migration and highlight the need to discern hepatitis A infection from vaccination status when assessing the effectiveness of vaccination using seroprevalence data.