Objective
To estimate the average treatment costs of pneumonia and meningitis among children under five years of age in a tertiary hospital in Hanoi, Vietnam from societal, health sector and household perspectives.

Methods
We used a cost-of-illness approach to identify cost categories to be included for different perspectives. A prospective survey was conducted among eligible patients to get detailed personal costing items.

Results
From the perspective of the health sector, the mean costs for treating a case of pneumonia and meningitis were USD 180 and USD 300, respectively. From the household's perspective, the average treatment costs were USD 272 for pneumonia and USD 534 for meningitis. When also including indirect costs, the average total treatment costs from the societal perspective were USD 318 for pneumonia and USD 727 for meningitis.

Conclusion
The study contributed to limited evidence on the high treatment costs of pneumonia and meningitis to the Vietnamese society, which is useful for a cost-effectiveness analysis of Haemophilus influenzae type b vaccine or other relevant disease preventions. It also indicated a need to re-evaluate the health insurance policy for children under 6 years old, so that the unnecessarily high out-of-pocket costs of these diseases are reduced.