In a retrospective study the clinical management of 74 patients with aneurysmal subarachnoid haemorrhage (SAH) admitted in grade IV and V Hunt and Hess was examined. 39 patients (53%) were admitted within 24 hours after SAH, 29 patients (39%) between 24 and 72 hours after SAH, and 6 patients 8%) later than this time interval. The ruptured aneurysms were located at the anterior communicating artery complex in 34 patients (46%), on the middle cerebral artery in 19 patients (26%), on the internal carotid artery in 12 patients (16%) and at the vertebro-basilar artery complex in 9 patients (12%). In 38 patients (51%) no surgical attack on the aneurysm was performed. 19 (50%) of these patients were in grade IV on admission and 19 (50%) in grade V. In 36 patients (49%) the aneurysm was clipped. Of these patients 29 (81%) were in grade IV and 7 (19%) in grade V. Of the 38 patients in whom no aneurysm surgery was done, 37 patients died, representing a mortality rate of 97%, one patient survived in grade III Glasgow Outcome Scale (GOS). Concerning the outcome in those patients with aneurysm clipping, of 19 patients in grade IV operated on early, 10 patients (53%) made a good recovery, 3 (16%) were left severely disabled and 6 patients (31%) remained in a vegetative state or died. Of the 10 patients in grade IV with delayed surgery 4 (40%) were in grade I and II postoperatively, 2 (20%) in grade III, and again 4 (40%) in grade IV and V GOS.(ABSTRACT TRUNCATED AT 250 WORDS)