Acute viral bronchiolitis constitutes the principal cause of acute lower respiratory tract infections in infants and children in Nord America. Every year 11% of infants younger than 1 year and 6% of those between 1 and 2 years are affected. Acute viral bronchiolitis is characterized by a first episode of respiratory distress associated to rhinorrhea, cough and fever, other symptoms such as vomiting, use of accessory intercostal muscles and irritability can be present. Mild symptoms presentation in bronchiolitis is very common, these patients do not require treatment or testing, only appropriate information on how to ameliorate respiratory symptoms and a well list of alarm signs for parents are frequently enough to send the patient home.