Background: Hepatitis B virus is one of the causes of the major health problem throughout the world. Hepatitis B vaccine is one way to control HBV infections effectively. The prevalence of HB infection shows a decreased effectivity of Hepatitis B vaccination. Objective: To discover the differences in anti-HBs levels between two schedules of vaccination recommended by the Indonesian Pediatric Society (at 2, 4, 6 months vs 2, 3, 4 months of age). Methods: This was an observational study on healthy babies comparing the effect of two treatment groups, each consisting of 30 subjects. Subjects were chosen by stratified random sampling. Blood samples were withdrawn three months after the subjects received their last dose of Hepatitis B vaccination, either in 2, 4, 6 months schedule (Group 1) or in 2, 3, 4 months schedule (Group 2). We used the independent t-test to assess the mean differences between the anti-HBs levels of the two groups. A p-value of<0.05 was considered statistically significant. Results: We found a significant difference in anti-HBs levels between Group 1 and Group 2 (820.06 mIU/ml vs 540.54 mIU/ml, respectively, p=0.002). Conclusion: Both vaccination schedules produced protective anti-HBs levels three months after the completed schedule. The anti-HBs level in group 1 produced higher anti-HBs level compared to Group 2.