A reappraisal of case histories of patients with ruptured intracranial aneurysms emphasized the importance of clinically recognizing severe spasm that contraindicates early angiography and large cerebral haematomas that require immediate evacuation. Observation from the day of haemorrhage is important; most recurrent episodes with cerebral signs in the first 10 days were due to spasm; haemorrhage was more common during the following two weeks. In many attacks the signs were not sufficiently distinctive for diagnosis of spasm or haematoma.