This study aims to evaluate the efficacy of HBV vaccination as an alternative preventive measure against de novo HBV infection in pediatric living donor liver transplantation (LDLT). Sixty recipients were enrolled in this study. Thirty received grafts from anti-HBc(+) donors, and another 30 received grafts from anti-HBc(-) donors. HBV vaccine was given pretransplant to every candidate. Posttransplant, lamivudine was routinely given to recipients receiving anti-HBc(+) grafts for about 2 years. Forty-seven (78%) recipients achieved high levels of anti-HBs titer (>1000 IU/L). Two (3.3%) recipients developed de novo HBV infection where one received an anti-HBc(-) graft and another received an anti-HBc(+) graft. Both recipients were in the lower anti-HBs titer group (<1000 IU/L). The incidence of de novo HBV infection was significantly higher in the lower titer group (15.4% vs. 0%, p = 0.04). The median follow-up period was 51 months in recipients with anti-HBc(-) grafts and 57 months in those with anti-HBc(+) grafts. Active immunization is an effective method to prevent de novo HBV infection. It can result in high levels of anti-HBs titer (>1000 IU/L) which may prevent de novo HBV infection in pediatric patients with efficient primary vaccination undergoing LDLT.