Introduction: Bronchiolitis is an acute infectious disease of viral etiology with diffuse inflammatory condition of the lower respiratory tract (bronchioles), having an acute presentation. It is one of the main reasons for hospitalization in patients in their first year of life, thus causing expense and concern for the health system in the world. OBJECTIVE: To determine the risk factors associated with bronchiolitis in infants at the Regional Hospital of Loreto during the period 2021 - 2023. MATERIAL AND METHODS: An analytical observational study of the case control type will be carried out, with a prospective design that will collect data in a time interval from July 2021 to December 2023. The study universe will consist of all infants admitted to the department of pediatrics of the HRL "Felipe Santiago Arriola Iglesias" with the diagnosis of bronchiolitis during the mentioned period. T...