Background: Vaccination against hepatitis B virus is an effective tool for prevention, however, the level of anti-HBS is influenced by various factors. Thus, in the present study we have evaluated the anti-HBS levels in vaccination children against hepatitis B referring to Amirkola hospital in Babol in 1999.

Materials and Methods: 100 children had enrolled for this cross sectional study, all of whom were under 7 years old and had received the last dose at least 3 months ago. 5ml of peripheral blood samples were obtained and checked for anti HBS and anti HBC.

Results: 84.5% had complete and regular vaccination program whereas 15.5% had complete but irregular vaccination. 87.6% of children with complete vaccination (Either regular or irregular) had anti-HBS titer of ?10 IU/lit (Protective level), among which, 28.8% had titer of 10-100 IU/lit and 58.8% had titer of ?100 IU/lit. The mean titer of anti HBS was 379.6 and 340 IU/lit in children aged 1-2 and 5-6 years, respectively.

Conclusion: Results have revealed that anti HBS protective level following the routine immunization program is relatively satisfactory. Needless to say, further prospective studies could determine the influential factors.