In a consecutive series of 219 patients with a ruptured aneurysm of the anterior part of the circle of Willis, 119 patients (54%) made a good recovery and 67 (31%) died. Of 53 patients who did not have surgery, six (11%) made a good recovery and 37 (70%) died. Urgent surgery with evacuation of an associated significant intracerebral hematoma was performed in 30 patients; nine (30%) made a good recovery and 15 (50%) died. Delayed surgery was performed in 55 patients of whom 42 (76%) made a good recovery and two (4%) died. Early intracranial operation (within 48 to 60 hours after subarachnoid hemorrhage (SAH)) was performed in 81 patients who were in Grades I to III prior to surgery. Sixty patients (74%) made a good recovery, and eight died within a month. Five patients were severely disabled and died 2 to 8 months after SAH and surgery. In 17 patients, although the immediate postoperative course was uneventful, evidence of cerebral ischemia developed 4 to 13 days after the bleed and resulted in death in eight patients. A poor outcome was correlated with a history of elevated blood pressure before SAH. Seven patients, of whom six were women of child-bearing age, demonstrated pronounced vasospasm on postoperative angiography; nevertheless, they remained well and free from ischemic symptoms after surgery. Early operation combined with removal of subarachnoid clots and rinsing the basal cisterns does not eliminate the risk of delayed ischemic dysfunction. Such early surgery, however, improves overall outcome by preventing recurrent bleeding, and may also reduce the frequency of hydrocephalus.