Because hepatitis A infection may be move severe in patients with chronic Jiver disease, we vaccinated 22 children who were hepatitis B surface antigen carriers against hepatitis A virus and anti-hepatitis A virus sera conversion rates after the first, second and third doses were 81.8% 90% and 100% respectively. t In this context, hepatitis B surface antigen positive patients with preexisting chronic liver disease rather than healthy carriers seems to be those as the highest risk of developing severe hepatitis A when superinfected with hepatitis A virus. According to our work results, we recommend to include persons who are chronic carriers of hepatitis B virus as well as those with chronic liver disease among candidates for anti-hepatitis A virus vaccination. This appears more important for children because they have a longer life expectancy and may elicit a better immune response.