Influenza in children is an important clinical, epidemiological and economic problem - but underestimated problem. The aim of the paper was to describe a current knowledge concerning epidemiology of influenza in children, including situation in Poland, its impact on ambulatory visits and hospitalizations. The beneficial effect of vaccination against influenza on economic and clinical issues was also underlined. It is estimated that annually 10-40% cases of febrile respiratory infections have influenza aetiology. In Poland, similar to other countries, the incidence of the diseases among children younger than 14 years is higher compared to the general population. However, the influenza vaccine coverage among children younger than 5 years in Poland is extremely low (<2%). Vaccinations against influenza in children are effective and safe and protect against the disease and its complications not only vaccinated children but also persons from close contacts. The most important method of prevention of influenza among children and adolescents aged 6 months-18 years is vaccination. Vaccination against influenza has been recommended in Poland since 1994. More educational activities addressed for patients and medical professionals are required to increase the influenza vaccine coverage among children and adolescents in Poland.