Neuropsychological testing of 48 patients who had undergone operation for subarachnoid hemorrhage (SAH) due to aneurysm was performed. Before this, the patients had their level of neurological recovery classified by neurosurgeons (37 good outcome vs. 9 poor outcome). These clinical categories correlated well with the results of neuropsychological testing. The degree of psychological impairment was related to age. The mean duration between SAH and clipping of the ruptured aneurysm was 4.6 days (range, 1-16 days), and 59% had operations on or before Day 3 post-SAH. Of the 37 patients with good neurological outcome, 26 patients had good neuropsychological outcome (no more than mild deficit). Poor neuropsychological outcome was associated with age and anterior communicating artery aneurysms. The incidence of significant neuropsychological deficit was considerably less than in previous reports, and possible explanations are discussed.