To ascertain the economic feasibility of a pediatric tetravalent dengue vaccine, we developed and calibrated a cost-effectiveness model of vaccinating children at 15 months in Southeast (SE) Asia using a societal perspective. We assumed that full immunization would require two doses at prices of US$ 0.50 and US$ 10 per dose in the public and private sectors, respectively. The gross cost per 1000 population (of all ages) of the vaccination program would be US$ 154. Due to projected savings in dengue treatment, the net cost per capita would be only US$ 17 (89% below the gross cost). The cost per disability adjusted life year (DALY) saved by a pediatric vaccine would be US$ 50, making the potential vaccine highly cost-effective. Eventually, vaccination may be able to replace environmental control as a strategy for dengue prevention and be cost saving.