In the autumn 2009 in Poland there was an outbreak of influenza A(H1N1)v, approximately 1/3 of confirmed cases in children younger than 14 years. The aim of the study was an epidemiologic and clinical characteristics of pediatric patients with influenza A(H1N1)v and evaluation of antiviral treatment safety. The medical records of 100 children with confirmed influenza A(H1N1)v were reviewed. 48% of children had risk factors for severe clinical course, including 23 younger than 2 years. The most common symptoms were fever (89%) and cough (68%). In 20% children pneumonia was diagnosed, other complications were uncommon. 4 patients required mechanical ventilation and 3 died, all with severe underlying conditions. In 62% of patients oseltamivir was used and it was well tolerated.