Early coma is common in severe craniocerebral trauma, and more than half of the comatose patients who have not regained consciousness for more than 6 hours die. About 10% of all craniocerebral traumas (20% of survivors) remain unresponsive for one month after injury, while the rest move from coma to awakening with progressive functional improvement. Patients who remain unresponsive for more than 1 to 3 months may develop a vegetative state, which manifests as the presence of natural sleep-wake cycles but lacks the characteristics of cortical judgmental behavior. Patients in a vegetative state for 1 month after injury may still experience qualitative recovery, but their chances of recovery decrease with time. Patients in a vegetative state for 1 month had a 50% chance of regaining a partial degree of perception and a 28% chance of improving their level of independence within 1 year. Patients who present in a vegetative state for at least 1 year or perhaps longer after injury may still revive. However, if awakening persists for a long time, severe disability is almost always left behind. Non-traumatic causes of the vegetative state (e.g., cardiac arrest) rarely awaken for more than 3 months overall. This suggests that patients with trauma combined with secondary hypoxic impairment are likely to have a worse prognosis than patients with simple impairment. The following factors may be positive predictors of the transition from an unresponsive state to awakening: low age, pupillary response and joint eye movements, decorticated posture rather than a decerebrate or flaccid state, early spontaneous eye opening, and lack of dependence on ventilators or hydrocephalus; the accuracy of these predictors is not yet sufficient to accurately guide early clinical decision making. The minimally conscious state, like the vegetative state, may serve as a transitional state in the recovery process or may also serve as a persistent functional state.