This chapter outlines the major differences that need to be considered when faced with neonates and children who require mechanical ventilation. It provides the anatomy, physiology and some particular examples of paediatric care. High frequency oscillatory ventilation (HFOV) is well established in neonatal practice having been in use for over two decades. Following a head injury, children may require intubation or ventilation for several different reasons. Humidification is the most important technical aspect of ventilation in children that may vary from adult practice. Staff involved in the ventilation of children needs to be aware of child protection issues. Recognition of features that may be seen in non-accidental injury such as a torn frenulum or other mouth trauma, and unusual bruises should give rise to discussion about possible causes. Equally, any injuries caused during line insertion or intubation should be carefully documented so that an appropriate explanation is clearly stated.