Although they are an important component of the human microbiome and the entire ecosystem, viruses are primarily known as causative agents of viral infections. They replicate with the help of the host cell and synthesize the components that make up new virus particles. Infection of the host leads to the development of viral diseases, which may be asymptomatic, with mild symptoms, or fatal. Children are most susceptible to viral and bacterial infections during infancy and early school age because their immune systems are not yet sufficiently developed and they spend time indoors with their peers. The most common symptoms of viral and bacterial illnesses are increased body temperature, runny nose, headache, and a rash in the form of reddish spots. Viral infections in children are transmitted by droplets and contaminated objects. In school children, as well as in adults, the common cold and gastrointestinal virus are the most common viral diseases. The most important prevention is the observance of personal hygiene and vaccination, which is carried out according to the implementation program and vaccination calendar for the current year, issued by the Ministry of Health. Vaccination against tetanus, tuberculosis, diphtheria, pertussis, mumps, polio, pneumococcus, measles, rubella, hepatitis B and Haemophilus influenzae type B are carried out as prescribed in the vaccination calendar. Recognizing that viruses and viral infections are constant companions of humans and evolution, this paper describes the major causes of viral infections in children and provides information that points to the importance of educating children about viruses and protection prechool and school-age children by implementing imunization programs.