The authors comparatively analysed the remote results of carotid endarterectomy and risk factors for unfavourable outcomes in patients with and without type 2 diabetes mellitus (DM). The outcomes of carotid endarterectomy were studied in a total of 168 patients, with the follow-up terms up to 8 years. Depending on the presence or absence of DM, the patients were divided into two groups. Group One comprised 79 patients with an atherosclerotic lesion of the internal carotid artery and accompanying DM, with Group Two consisting of 89 non-diabetic patients. There were no lethal outcomes in the early postoperative period. The composite measure 'lethality + stroke' in Group One amounted to 2.5% and in Group Two to 2.2%. In the remote period the survival rate was as follows: 65 (82.3%) people for Group One and 83 (93.3%) for Group Two, with the 5-year cumulative survival rate amounting to 75.1±6.4% and 92.5±3.0%, respectively. The index of freedom from acute vascular complications (myocardial infarction, ischaemic stroke) at 5 years in Group One was 54.2±7.2% and in Group Two 86.1±4.3%. Acute vascular complications were causes of lethal outcomes in 13 cases in the group with DM and in 3 cases in the group without DM. Death was most often caused by acute coronary complications. The index of freedom from restenosis at 5 years in Group One amounted to 74.5±8.0% and at 7 years of follow-up in Group Two to 92.3±7.3%. The risk factors for the development of acute vascular complications in diabetic patients according to the findings of the Cox regression analysis were as follows: age above 65 years, DM duration of more than 5 years; the level of glycated haemoglobin above 7.5%; a history of myocardial infarction; presence of degree III arterial hypertension. The risk factors for restenosis included: DM duration of more than 5 years, the level of glycated haemoglobin above 7.5% and presence of degree III arterial hypertension. The results of the study make it possible to regard carotid endarterectomy efficient and safe for both cohorts of patients (with and without DM). In the remote postoperative period, such parameters as survival rate, indices of freedom from acute vascular complications and restenosis turned out to be statistically significantly lower in diabetic patients than in non-diabetic, with the predominating coronary complications induced by insufficient assessment of the coronary reserve and the presence of occult forms of ischaemic heart disease. Long-term results may be improved by means of widening the indications for performing coronarography in patients with DM.