Secondary brain injury may occur early after severe traumatic brain injury due to hypoxia and/or hypotension. Prehospital care by ambulance paramedics has the goal of preventing and treating these complications and, thus, improving outcomes. In Australia, most ambulance services recommend paramedics attempt endotracheal intubation in patients with severe head injury. Even though most patients with severe head injury retain airway reflexes, most states do not allow the use of appropriate drugs to facilitate intubation. In contrast, recent evidence from trauma registries suggests that this approach may be associated with significantly worse outcomes compared with no intubation. Two states allow intubation facilitated by sedative (but not relaxant) drugs, but this has a low success rate and could worsen brain injury because of a decrease in cerebral perfusion pressure. For road-based paramedics, the role of rapid sequence intubation is uncertain. Given the risks of this procedure and the lack of proven benefit, this procedure should not be introduced without supportive evidence from randomised, controlled trials. In contrast, for safety reasons, comatose patients transported by helicopter should undergo rapid sequence intubation prior to flight. However, this is not authorised in most states, despite good supportive evidence that this can be safely and effectively undertaken by paramedics. Finally, there is evidence that inadvertent hyperventilation is associated with adverse outcome, yet only two ambulance services use waveform capnography in head injury patients who are intubated. Overall, current paramedic airway practice in most states of Australia is not supported by the evidence and is probably associated with worse patient outcomes after severe head injury. For road-based paramedics, rapid transport to hospital without intubation should be regarded as the current standard of care. Rapid sequence intubation should be limited to use within appropriate clinical trials, or patients transported by helicopter. For patients who are intubated, waveform capnography is essential to confirm tracheal placement and to prevent inadvertent hyperventilation.