To investigate how cognitive impairment is affected by the relief of bilateral carotid stenosis, chronic cerebral hypoperfusion was established through stenosis of the bilateral carotid common artery in adult Sprague-Dawley rats. Subsequently, the model rats received the intragastric placebo, donepezil (5 mg per kg), or surgery to relieve carotid stenosis after bilateral carotid common artery stenosis. After carotid stenosis was relieved, the cerebral blood flow values significantly increased, and P300 latency and escape latency in the Morris water-maze were significantly shortened. The concentrations of acetylcholine and norepinephrine in the dorsal hippocampus increased after carotid stenosis was relieved. Furthermore, P300 latency and escape latency were shortened in the relief-treated group compared to the drug-treated group, and acetylcholine levels in the relief-treated group were higher than the drug-treated group. No significant difference was found for the norepinephrine levels in the dorsal hippocampus between the relief-treated and drug-treated groups. Cognitive impairment can be significantly reduced by bilateral carotid stenosis relief, and the effect of relieving stenosis on cognitive dysfunction is superior to the effect of administering an acetylcholinesterase inhibitor.