The present study examined the nature of the amnestic syndrome following aneurysm of the anterior communicating artery (ACoA) in humans. Eleven ACoA and 13 subjects with intracranial hemorrhages (ICH) elsewhere in the brain were administered a battery of standard neuropsychological tests. The ACoA group performed significantly worse than the ICH controls on tests of delayed verbal memory and on the Wisconsin Card Sorting Test, despite significantly higher Full Scale IQ. No significant differences were observed between groups on tests of immediate recall, attention and concentration, and visuo-spatial functions, although the ACoA group tended to perform better on many of these tests. The results do not support the hypothesis that the cognitive impairments observed following ACoA aneurysm are the result of diffuse cortical damage. The role of specific anterior cerebral structures in defining the "ACOA syndrome" are discussed.