The study was to estimate total annual costs and unit costs for expanded immunization program in Thai Nguyen, 2009 and analyze structure of the annual costs and unit costs. The result indicated that total annual costs for expanded immunization program in. Thai Nguyen was 8,993,860,728 VND. Average cost for any antigen was 12,600 VND, average cost for a fully vaccinated child was 86,580 VND. Recurrent costs accounted was 8,471,737,708 VND, including labor costs, costs for preparation activities (communication, training, plan making...) and vaccine and consumed materials were 3,832,496,000 VND, 1,666,165,000 VND and 976,807,708 VND, in respectively. In conclusion, average cost for a fully vaccinated child was lower than the costs reported from other developing countries.