The Lombok Hepatitis B (HB) Model Immunization Project was the first mass infant HB immunization project in Indonesia. Key aspects were the procurement of low-cost HB vaccine, integration into routine infant immunization services, and delivery of the first dose in the home within 1 week of birth. The project achieved > 90% coverage with 3 doses of vaccine. The prevalence of HB surface antigen was 1.4% in infants who received 3 doses (with the first dose within 7 days of birth) and 3.0% in those who received the first dose > 7 days after birth, compared with a baseline prevalence of 6.2% P <.001 in each case). Most vaccine failures occurred in children born to HBe antigen-positive mothers. Antibody prevalence and titers did not correlate with protection. HB vaccine can be successfully integrated into the Expanded Programme on Immunization (EPI), strengthening the EPI and significantly reducing chronic HB infection.