Objective is to compare the predictive value of stump pressure (SP) and cerebral oximetry (rSO2) levels in the evaluation of ischaemic injury of the cerebrum during clamping of the carotid artery (CCA) without temporary shunt (TS). Methods We included 84 patients with an asymptomatic stenosis (>70%) of the internal carotid artery (ICA) who underwent carotid endarterectomy (CEA) under GA. Cerebral ischaemic tolerance (CIT) was determined on the basis of SP, rSO2 and ∆rSO2 (↓rSO2 from baseline) during CCA. The levels of S100 protein (S100) and neuron-specific enolase (NSE) were measured on each stage of the study. MRI was performed for all patients. Results There were no perioperative strokes and myocardial infarctions during the study. Temporary shutdown of blood flow in CAs during CEA is accompanied by a significant elevation of S100, NSE concentration with their subsequent restoration (three days after surgery). ROC analysis showed that none of the methods for CIT assessment (SP, rSO2 and ∆rSO2) was a valuable predictor of cerebral damage during CEA. Conclusion SP with a threshold value of ≤40 mmHg has an average quality of prediction (AUC = 63). ∆rSO2 of ≥20% and a threshold value of rSO2 ≤ 40% have an unsatisfactory quality of prediction (AUC < 60).