Objectives: To provide a comprehensive review of the prevalence of selected hepatitis B virus (HBV) seromarkers and to identify variability in seroprevalence across the 14 World Health Organization (WHO) sub-regions and among special groups and populations. Methods: Analyses involved 568 papers and 736 population studies. The complete data set included 21, 838, 249 individuals and covered the 14 WHO sub-regions. Results: Of the 687 studies that assessed hepatitis B surface antigen (HBsAg) seroprevalence, 30% had low (<2% affected), 36% had intermediate (2-8% affected), and 34% had high (>8% affected) endemicity. Median HBsAg seroprevalence differed by selected populations and among geographic regions. Overall, median seroprevalence was highest for 'other' populations, followed by patients, then by pregnant women and children. Median seroprevalence of antibody to hepatitis B core antigen (anti-HBc) followed a similar endemicity pattern to that of HBsAg across the 14 WHO sub-regions. Median seroprevalence of hepatitis B e antigen (HBeAg) showed considerable variability within each population group, with the greatest potential for infectivity seen among children. Conclusions: This population-based review provides a comprehensive assessment of the burden of HBV throughout the world. Significant differences in seroprevalence exist between WHO regions, study populations, and seromarker testing methods. The results presented in this study will enable health professionals to track worldwide reported seroprevalence of hepatitis B markers. (C) 2010 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.