Cerebrovascular complications of AIDS have been reported as high as 34% in post mortem series. Most patients suffer from ischaemic strokes but there are a number of reports of patients presenting with subarachnoid haemorrhage (SAH) related specifically to aneurysm rupture. We present three patients with advanced HIV disease and low CD4 counts who present with SAH. In two of the patients the haemorrhage appeared to be caused by intracranial artery dissection which, to our knowledge, has not previously been described. Both patients were successfully treated endovascularly, one with segmental vessel trapping and the other with partial coil embolization of a false aneurysm. The pathological basis for HIV related arteriopathy is discussed in relation to these cases.