OBJECTIVE To determine by literature review the effect of carotid endarterectomy (CEA) as a modulator of cognitive function in patients with carotid arterial disease. Derive recommendations for standardising cognitive testing of patients with carotid arterial disease. METHODS The English language literature was interrogated using a CD-ROM driven medline search using carotid endarterectomy and cognitive function as keywords between 1986-1995. These subsets were scanned and papers of direct relevance or commonality were selected. Cited papers prior to 1986 from these references were then sought directly. RESULTS There are few controlled studies reporting on the effect of CEA. There is no consensus in the literature for the effect of CEA on cognition or which tests should be used. Studies reporting a benefit for CEA lack a control group and fail to eliminate the effect of practice. Reports suggesting cognitive impairment following CEA performed follow-up tests early. CONCLUSIONS There are many methodological problems with the study of cognitive function before and after carotid endarterectomy and wide disagreement in the interpretation of results. Further studies should contain control groups, use tests resistant to practice and be performed when the effects of surgery and anaesthesia are passed.