Continuous intravenous sedation is often used during the intensive treatment of severe head injury. Hypnotic agents may prevent or treat the brief episodes of intracranial hypertension associated with nociceptive stimuli. However there is yet no clinical data in the literature showing beneficial effects of continuous sedation on intracranial pressure control or outcome in severe head injured patients. Sedation should be primarily administered to allow good conditions for intensive treatment. Benzodiazepines are sedatives with limited systemic side effects. Midazolam is very convenient because its short duration of action allows reasonable recovery time following prolonged administration. The abrupt reversal of sedation by means of specific antagonists may induce significant elevation of cerebral blood flow and intracranial pressure and should be avoided.