Publisher Summary Since Sanders in first published a description of intraventricular haemorrhage, there have been numerous reports, mostly morphological and clinical case histories, in which attention has been drawn to the various forms of haemorrhage and abnormal clinical symptoms and courses, to spontaneous recoveries and to cases subjected successfully to operation, but so far in the neurosurgical literature there have been no systematic examinations. A review of our personal case material has recently been undertaken and shows the principal causes and distribution of the haemorrhages. Out of 145 cases of spontaneous intracerebral haematoma, approx. half were due to cerebral vascular diseases, mostly as a consequence of hypertension, while the other half were due to cerebral vascular malformations. Owing to the fact that neurosurgeons are being increasingly confronted with cases of vascular diseases of the brain, the clinical and specific diagnostics and the treatment of intracerebral mass haemorrhages and of the frequently associated intraventricular haemorrhages have so much improved in recent years that nowadays half these patients can be saved if operation is performed immediately. A policy of waiting or even resignation is no longer justified; instead, every case of apoplexy with blood in the CSF must be diagnosed as rapidly as possible, and mass haemorrhages of whatever origin must be treated by operation.