A series of 31 patients with good neurological 6-month outcomes (Glasgow Outcome Scale = I) was examined with a battery of cognitive tests 1 to 5 years after aneurysmal subarachnoid hemorrhage (SAH) and early operation. The results showed a marked disability in 28 to 62% of these patients in the subtests of a complex choice reaction task. Short-term memory was impaired in 53% of the patients neuropsychologically examined, whereas 21% of them had a reduced long-term memory. Concentration was impaired in 7 to 16% of the SAH patients. Also, 10% of the patients rated Glasgow Outcome Scale = I had an indication for an aphasic language disturbance. Multivariate analysis proved significant harmful effects of the severity of the bleeding seen on computed tomographic scan (Fisher scale) on information processing and word-finding capacity. Patients who were older at the time of the SAH were significantly more disturbed in concentration, short-term memory, and information-processing capacity at follow-up. It can be concluded from these results that a good neurological outcome (Glasgow Outcome Scale = I) does not exclude persisting neuropsychological deficits. Therefore, the value of the clinical use of the Glasgow Outcome Scale is limited. As a consequence, a differentiated neuropsychological examination is proposed to evaluate the exact outcome of SAH patients.