OBJECTIVES During the influenza epidemic period (2009-2010) 17 % of  Ukrainian population were sick. The aim was to assess the dynamics of incidence rates. We analyzed the costs of treating influenza and acute respiratory infections (ARI) in the four stages of medical care: 1 - primary care (PCP), 2-out-patient, 3-hospital, 4-intensive care unit during the period 2009-2010 (pandemic) vs 2010-2011. METHODS We used the statistic data of the MoH of Ukraine, the incidence of influenza and ARI, and method "cost of illness" per 1 patient. RESULTS In 2009-2010 influenza rate and ARI was 472,6 per 100000 population. The vaccination coverage was 239,104 people, that representing 0.518% of the total population. In 2010-2011 the ifluenza rate and ARI was 420.9 per 100000, respectively. The vaccination coverage was 602911 persons during 2010-2011 years, that’s 1,312% of the total population. We obtained the following costs per 1 patient: 1. Flu patients at PCP, average number of visits/patient in 2009-2010 were 7753635 sick persons, 2010-2011– 7502008 sick persons. Total cost of the disease was 80,39 UAH per 1 patient  (1 Euro=10 UAH on 01.06.2011).  2. Flu patients in out-patient clinic during 2009/10  were registered 1962839 request for medical assistance about influenza and ARI. In the season, 2010/11 - registered 1785102 who needed medical care for influenza and ARI, total cost was 202,07 UAH. 3. Flu patients in hospital during 2009-2010 were hospitalized 47108 persons. Total cost of the disease was 728, 85 UAH. 4. Flu patients in intensive care unit – the total cost of the disease was 2543,08 UAH. CONCLUSIONS Established the high costs for the hospitalization were 2543,08 UAH  per 1 patient comparіng with 80,39 UAH at PCP. Govermental program to prevent influenza by vaccination can to reduce the cost of  flu treating.