The case histories of 4 patients with a severe cranio-cerebral injury were described. The clinical pictures and the post mortem findings showed much resemblance. The clinical course was divided into three different periods: The first lasting from the injury till the moment of artificial respiration, the second from then on till the clinical evidence of death of the brain and the third from then on till death. On post mortem examination the brains were remarkably soft and friable. Microscopic examination revealed necrosis of both the grey and white matter of the whole brain. It was supposed that this was due to intravital autolysis. Although death followed 4–9 days after the brain accident, the primary lesions (caused by the injury itself) were not accompained by a normal reaction of leucocytes or glia cells. A most interesting feature in all four cases was a very extensive and recent thrombosis of the carotico-basilar arteries. This thrombosis was the result of traumatic lesions of the vessel wall in combination with stasis of the blood caused by local vasoparalysis and general hypotension. It is likely that the unusual extent of the intra-arterial thrombosis was only possible thanks to the artificial survival of the patient. The problem arises whether the intravital death of the brain was the result of the thrombosis or whether the thrombosis developed during the state of deanimation.