Asthma is a multifactorial disease in which many factors play a role in its development and exacerbations. Viral infections are known to be the main cause of asthmatic exacerbations and are often the first manifestation of asthma in preschool age. However, there is much evidence suggesting a role of viral infections even in asthma development. Respiratory Syncytial Virus (RSV). has been first associated with an increased risk to develop asthma, but recently new viruses have been proposed to be involved in asthma pathogenesis. Further studies will be needed to demonstrate a causative role of viral infections in asthma development, in order to implement preventive strategies in high-risk children.