The article presents the clinical observation of a premature infant with bronchopulmonary dysplasia who developed severe acute respiratory syncytial virus (RSV) bronchiolitis. The different data were presented in the article. We demonstrated the epidemiology, etiology, diagnostics, and therapy of acute bronchiolitis. The passive immunization with palivizumab and its efficacy in preventing RSV lower respiratory tract infection showed. The number of it prescriptions in Moscow’s region have estimated in the article. Analysis of the therapy, clinical, laboratory and radiological findings of acute RSV bronchiolitis was analyzed in a comparison of modern medical literature. © 2022 Geotar Media Publishing Group. All Rights Reserved.