Recent literature has provided evidence of a link between early RSV infection and chronic respiratory morbidity (recurrent wheezing, reactive airway disease and asthma). The mechanism of this association is not well understood but both genetic and environmental factors are involved. The classical studies from Sweden, Tucson and Finland are briefly summarized. Moreover new data concerning a recent multi-center international study on this topic are presented. The study, which enrolled 191 preterm infants (<or=35 wGA) who had received pelivizumab before 6 months of age and 230 who had never received pelivizumab, suggests that prevention of respiratory syncytial virus (RSV) lower respiratory tract infections (LRTIs) with pelivizumab may reduce subsequent recurrent wheezing in premature infants. The INDEX study, a prospective study, will provide a useful contribution to the definition of epidemiological data on respiratory infection in preterm infants in Italy. Additional research is required to more fully understand the mechanism by which RSV leads to wheezing.