Objectives: HBV infection is a contagious disease that maytransmit vertically from mothers to their neonates or horizontallyby blood products and body secretions. Over 50% of Iraniancarriers have contracted the infection perinatally, making thisthe most likely route of transmission of HBV in Iran. This studyassesses the serologic markers of HBV in children born to HBsAgpositive mothers who received HBIG and 3 doses of HBV vaccine. Methods: To evaluate the effectiveness of vaccination againstHBV, a study was conducted on 95 Children, born to hepatitisB surface antigen (HBsAg)-positive mothers, who had receivedHepatitis B Immune Globulin and HBV vaccines during 2004-2008. All children were tested for the presence of HBsAg, anti-HBs and anti-HB core antigen (anti-HBc). Results: Among an estimated 30000 pregnant women during thefive year study, about 130 (0.42%) were HBV carriers. Ninety-fivechildren from these mothers were enrolled in this study. Only onechild (1.1%) was HBsAg positive, while 88.4% of children wereAnti-HBs Positive. Eleven children (11.6%) were exposed to HBVas shown by the presence of anti-HBc. A significant difference wasobserved between the children's age and Anti-HBs (p=0.0001). Conclusion: Passive-active immunoprophylaxis of high risk babieswas highly efficacious in preventing perinatal transmission of theHBV carrier state. Also, evaluation of serologic markers in HBVinfected people is important for designing the strategies for diseasecontrol.