OBJECTIVES:  Influenza which is imposed a considerable economic and social burden is a common cause of influenza-like illness among children. This study was conducted to estimate cost of illness based on provider perspective of influenza. METHODS:  A retrospective study was conducted between January 2013 and December 2015 at at Ho Chi Minh city Hospital of Tropical Diseases. Demographic and clinical information was collected from medical records. Treatment cost are composed of cost of hospital bed, cost of diagnosis test, cost of X-ray/Imaging, cost of operation, cost of pharmaceuticals and cost of consumable material. RESULTS:  Average cost per episode of all aged group was 112.58±239.60 USD, the highest cost was contributed by Adults group (313.28±560.50 USD), whereas the lowest cost was Children group (80.62±120.83 USD). According high risk factor group, average cost per day is 42.14 USD for any cardiovascular disorders group; diabetes-cardiovascular patient (41.15 USD), and elderly patient groups (48.52 USD). CONCLUSIONS:  Direct medical cost of influenza-related hospitalizations imposes a heavy burden on patients and their families in Vietnam. Further study is needed to provide more comprehensive evidence on the economic burden of influenza.