Conjugate Hib vaccines are costly and Hib meningitis incidence in Thailand is relatively low comparing to western countries; a decision tree model was used for cost-benefit analysis (CBA) of a universal conjugate Hib vaccination program in Thailand. Tangible and intangible costs and benefits of the program, occurring from birth to 60 years of age from the provider and client perspectives, were included in the cost analysis. With a birth cohort of 740,109, at a cost of USD 8 million (THB 288 million), the program will potentially prevent 77 deaths, 19 cases of severe disability, 135 cases of meningitis, and 628 cases of pneumonia resulting in a net benefit of about USD 70 million to society. The program is cost-effective only if intangible benefits are included in the model.