Acute respiratory infection is the most common infectious disease in humans, and children are the most commonly affected age group. With their high frequency, ARI significantly affect the daily functioning of society (absence from work, school, nursery school), but also the health system (prescription of antibiotics, payment of sick leave). The most common viral agents of ARI in children are: respiratory syncytial virus, human metapneumovirus, influenza virus, parainfluenza virus, adenovirus, rhinovirus, human bocavirus, coronavirus and enterovirus. The aim of this thesis is to present an overview of the basic characteristics of the most common viral agents and the available laboratory diagnostics of viral infections, with an emphasis on methods of rapid diagnostics. Laboratory diagnostics of viral infections can be divided into direct and indirect methods. By indirect methods we mean serology, which is not routinely used in the case of ARI. Direct methods are further divided into virus isolation and non-cultivation methods. Virus isolation is a reliable method of virus detection, but due to its complexity and long duration, it is also not suitable for routine use in diagnosis of ARI. Non-cultivation methods (antigen detection and molecular methods) belong to methods of rapid diagnostics. The usage of rapid diagnostic methods in the daily work of clinicians can significantly influence the treatment of patients and lead to a reduction of antibiotic prescribing rate, early recognition of viral circulation within the population, and ultimately to an overall reduction in the cost of treating a patient with ARI.