Aim To observe the efficacy and safety of donepezil on improving cognitive impairment after stroke. Methods 86 patients with cognitive impairment after stroke were randomly divided into treatment group(44 cases) and control group(42 cases).The treatment group were treated with donepezil hydrochloride capsules on the basis of the conventional therapy,5 mg,qd,after 4 weeks,increasing to 10 mg,qd.The control group were treated with piracetam on the basis of the conventional therapy,800 mg,tid orally.Two groups were treated for 12 weeks.Cognitive function and activities of daily living score of 2 patients were detected before and after treatment. Results After treatment,significant improvement rate and total effect of the treatment group were significantly higher than that of the control group(P><0.05),mini-mental state examination MMSE,visual recognition,image memory,digit span and the 100 → 1 score of the treatment group were significantly higher than before treatment and the control groups(P><0.05 or P><0.01),ADL scores of the treatment group were significantly lower than before treatment and the control groups(P><0.05 or P><0.01),There was no significant difference between before and after treatment in visual recognition,image memory,digit span and the 100 → 1 score of the control group(P>0.05).There was significant difference between before and after treatment in MMSE,ADL of the control groups.Donepezil side effects were minor. Conclusions Donepezil significantly improved cognitive function after stroke,and activities of daily living in patients with high security.