The prognosis of prolonged cardiac arrests is generally related to brain damage due to the cerebral anoxia. A neurological worsening leading to irreversibility is sometimes associated with an increase in intracranial pressure. We studied for 5 years the early intracranial and cerebral perfusion pressures in 84 patients with deep anoxic coma after cardiac arrest. Intracranial pressure monitoring was set up as soon as possible with an extradural screw over a period of 6 days. No complications occurred using this technique. We recorded the percentage of patients suffering from intracranial pressure peaks over 15 mmHg (a), over 25 mmHg (b) or cerebral perfusion pressures drops under 50 mmHg (c). We obtained during the 1st day of monitoring: (a) 46.4%, (b) 21.4%, (c) 39%; during the 2nd day: (a) 73.6%, (b) 26.3%, (c) 55.9%. Eight patients (9.5%) were still alive after a couple of months, 4 of whom had no neurological sequelae; among the 76 non-survivors 63 (82.9%) had died because of cerebral anoxic damage. A daily comparison between survivors and non-survivors points out that the survivors' intracranial pressures were always lower than in the non-survivors and the survivors' cerebral perfusion pressures higher than in the non-survivors. Moreover, none of the patients showing intracranial peak pressures over 25 mmHg survived without after-effects. It is clear that many patients suffer early periods of high intracranial pressures and low cerebral perfusion pressures leading to a bad neurological prognosis. Intracranial pressure monitoring may allow assessment of patients' neurological status and prognosis after cardiac resuscitation.