Small cohort studies from countries where both HIV and HBV are endemic demonstrate prevalence rates of chronic hepatitis B in HIV-infected children of between 1 and 49%. While data on coinfected children are limited, results from studies in adults with HIV/HBV coinfection raise the concern that coinfected children may be at a higher risk of liver disease, hepatic fibrosis and cirrhosis. With the scale-up of combination antiretroviral therapy worldwide, of which lamivudine is included in most first-line regimens, coinfected children treated with lamivudine risk development of HBV resistance mutations. This article summarizes the current literature relevant to HIV/HBV coinfection in children, the options for treatment and highlights priorities for future research.