Background: Hepatitis B infection (HBV) remains a significant clinical and public health problem and is hyperendemic in Nigeria. In highly endemic regions, infections spread from mother to child, or by horizontal transmission, with the burden of infection being highest in under-fives. Nigeria has a large number of orphans and vulnerable children, with reports of high seroprevalence of HBV infection in orphanages. There is no such report from our locality, despite having a high number of orphans. Therefore, this study was set to determine the risk factors, seroprevalence and infectivity of HBV in children resident in orphanages in Owerri, Southeast Nigeria. Conclusion:There is high seroprevalence and infectivity of HBV in orphanages in Owerri, Southeast Nigeria. Sharing of towel and barbing devices and circumcision were the significant risk factors for HBV infection. There is need for continuous health education on Hepatitis B infection, improved standard of living and immunization coverage in orphanages in developing countries.