A therapy refractory brain edema is causally responsible for the death of approximately 50% of patients following severe craniocerebral trauma. The development of a brain edema which cannot be controlled by conservative means is also the most frequent cause of death with cerebral emergencies not caused by trauma. The cerebral perfusion pressure (CPP), which is the decisive factor for sufficient cerebral oxygenation, can be calculated on condition that the mean arterial pressure (MAP) and the intracranial pressure (ICP) are continually monitored: (CPP = MAP-ICP). On the basis of neurological observations, the computer tomographical results and the jugular vein oxymetry, an incipient cerebral decompensation and consequently the failure of the ongoing conservative treatment becomes apparent at an early stage. At this point at the latest, a bitemporal craniectomy should be considered for treatment. A drop in CPP to below 70 mmHg for adults and 50 mmHg for children is regarded as the intervention limits. Our experience shows that the outcome can be improved if the time of the bitemporal craniectomy lies before that of the cerebral decompensation.