Objective To investigate the value of adiponectin level in the diagnosis of cognitive impairment in patients with acute cerebral infarction. Methods A total of 141 patients with acute cerebral infarction admitted to the Department of Neurology， the Second Affiliated Hospital of Xinxiang Medical College from October 2018 to April 2020 were enrolled by cluster sampling method. The patients were divided into cognitive impairment group （n=73） and non-cognitive impairment group （n=68） for comparative analysis. Peripheral venous blood was taken from the patient in the morning after admission， and serum adiponectin levels were measured for comparison between groups. The neurological deficit and cognitive impairment were analyzed by National Institutes of Health Stroke Scale （NIHSS） and Montreal Cognitive Assessment Scale （MoCA）. Pearson correlation analysis was used to analyze the correlation between MoCA score and serum adiponectin level in patients with acute cerebral infarction. The receiver operating characteristic （ROC） curve was drawn to analyze the value of serum adiponectin level in the diagnosis of cognitive impairment after cerebral infarction. Results There was no significant difference in baseline data and NIHSS score between the two groups （P ＞ 0.05）. The MoCA score and serum adiponectin level of patients with cognitive impairment after cerebral infarction were significantly lower than those without cognitive impairment after cerebral infarction （P ＜ 0.01）. Pearson correlation analysis showed that there was a positive correlation between MoCA score and serum adiponectin level in patients with acute cerebral infarction （r=0.411，P ＜ 0.05）. Patients with cognitive impairment after cerebral infarction were divided into lacunar cerebral infarction group （n=51）， small area cerebral infarction group （n=11） and large area cerebral infarction group （n=11）. There was no significant difference in the level of serum adiponectin among the three groups （P ＞ 0.05）， but the level of serum adiponectin decreased with the expansion of cerebral infarction area. The area under the ROC curve of serum adiponectin level in predicting cognitive impairment after cerebral infarction was 0.694 （95%CI=0.607- 0.781， P＜ 0.05）， and the sensitivity and specificity were 48.5% and 84.9% respectively. Conclusions The level of adiponectin in patients with cognitive impairment of acute cerebral infarction is low. The level of serum adiponectin can provide certain diagnostic value for cognitive impairment after cerebral infarction