After a survey of data in the literature the authors have used four criteria for the identification of the supraacute extradural hematoma:--an interval of maximum two hours between the occurence of the trauma and the performance of the intervention or exitus;--a severe cerebral syndrome with primary brutal coma, or coma that has developed in the above-mentioned interval;--the discovery during intervention of a "developing" hematoma, mostly as fluid, and the identification of the source of haemorrhage;--persistent cerebro-ventricular collapse after evacuation of the hematoma, that makes necessary the application of operative procedures for achieving recovery. Two of the 5 observations of the authors are presented, both in males, aged 22 and 73 years respectively, in whom surgery was performed in an interval of less than two hours. All the patients were comatose when the intervention was carried out, and 3 of them had a temporal fracture. The diagnosis was made by angiography. During surgery a fluid extradural hematoma was found, and the source of the haemorrhage was identified in three of them as a major branch of the median meningeal artery. One death was recorded due to recidive of extra-dural hematoma, associated with cerebral contusion and cerebral edema. In all the five patients the authors found cerebro-ventricular collapse that was recovered by introduction of physiologic saline and air through the lumbar route during the intervention.