Over the last 8 years, 22 consecutive cases of subarachnoid haemorrhage were found to have no obvious cause on angiography. The age, neurological status and CT-scan appearance in 16 cases were studied together with the completeness and quality of the angiogram. Limited angiography was done in cases with advanced age, poor neurology or severe hypertension. There is a need for more repeat angiographic studies in the presence of vasospasm whether focal or generalised, as indicated by the fact that only 5 out of the 17 cases with vasospasm had repeated satisfactory studies.