Bronchiolitis is the commonest reason for hospital admission in infancy and the most frequent cause of acute respiratory failure in children admitted to paediatric intensive care units in the UK and North America. The respiratory syncytial virus accounts for most cases of bronchiolitis, however, new virus isolation techniques have led to the discovery of previously unrecognised viruses, including the human metapneumovirus and bocavirus which also play a significant role. The main developments in bronchiolitis management in recent years relate to the use of immunoprophylaxis; a number of other therapies such as the use of heliox are currently being investigated. Supportive therapy remains the mainstay of management with limited or no evidence of benefit for most other pharmacological treatments. This article summarises the current understanding of the different bronchiolitis phenotypes, with a brief description of outcomes and a review of the evidence for the various therapeutic interventions.