Angiography in patients with subarachnoid hemorrhage secondary to aneurysm gives precise information on the location and size of the aneurysm and the presence of spasm but gives incomplete information on ventricular size, size and location of hematoma, and extent of infarction. CT demonstrates precisely brain or intraventricular hematoma and, at times, subarachnoid hemorrhage; indicates the extent of infarction; and rapidly documents the degree of hydrocephalus. Infarction secondary to spasm, hematoma, and hydrocephalus are readily differentiated. The CT examination may be repeated as often as necessary without patient discomfort or morbidity. Serial scans allow rapid assessment of change in ventricular size, development and persistence of infarction, and change in size of hematoma.