Influenza has always been and still is the cause of considerable morbidity and, consequently, frequent multiorgan complications, often irreversible and even fatal. It is an acute infectious disease caused by type A, B and C viruses, members of the family Orthomyxoviridae. Infections caused by the influenza virus are reported in every epidemic season. Influenza infections should be considered not only in the aspect of health, but also in the quantifiable, measurable economic aspect. For many years, influenza has been one of the basic priorities of public health. Virological and epidemiological surveillance of influenza, which is implemented in each epidemiological season, is one of the key elements of public health. Virological surveillance involves laboratory confirmation of infection, while epidemiological surveillance involves monitoring of actual and suspected cases of influenza. Laboratory diagnosis is performed to confirm influenza virus antigen in the material collected from the patient, isolate the virus and confirm viral infection based on increased serum antibody levels. Isolating influenza viruses that circulate in a given epidemiological season is necessary to prepare a vaccine against influenza. An early and correct virological diagnosis of respiratory infection, with particular reference to influenza, is currently of great importance in terms of both medical and economic aspects. The paper discusses influenza diagnostic methods currently used in Poland to help physicians in deciding whether laboratory confirmation of diagnosis is justified in the aspect of possible treatment to avoid influenza-induced multiple organ complications.