The aim of this study was to investigate changes in cognitive function following carotid endarterectomy (CEA). In 74 asymptomatic CEA patients cognitive function, depression, laterality and severity of stenosis, cerebral Computer Tomography results, and ischemic heart diseases were measured preoperatively. The sample included 31 patients with dementia and 43 patients without any symptom of dementia. Cognitive function was measured again at 3 months postoperatively using a brief standardised test. After controlling for cognitive function and depression at baseline, cognitive function improved significantly at 3 months after CEA in both patients with and without dementia. CEA may offer more than reduced stroke risk to patients, independent of cognitive function.