〔Abstract〕 Objective To analyze the relationship between blood pressure variability and cognitive dysfunction in patients with acute cerebral infarction (ACI). Methods The clinical data of 80 patients with ACI admitted to the First Hospital of Nanping Affiliated to Fujian Medical University from June 2018 to June 2021 were retrospectively analyzed. They were divided into cognitive impairment group (score < 26) and non-cognitive impairment group (score ≥ 26) according to the Montreal Cognitive Assessment Scale (MoCA). The baseline data of patients were collected to analyze the relationship between the blood pressure variability index [24h diastolic blood pressure variability coefficient (24h DCV), 24 h systolic blood pressure variability coefficient (24h SCV), 24 h diastolic blood pressure standard deviation (24h DSD), 24 h systolic blood pressure standard deviation (24h SSD)] and cognitive impairment in ACI patients. Results Among 80 patients with ACI, 31 patients had cognitive impairment, the incidence was 38.75%; Multivariate logistic regression analysis showed that blood pressure variability indicators were risk factors for cognitive dysfunction in patients with ACI (OR > 1, P < 0.05); The results of the subject working curve (ROC) showed that the area under the curve (AUC) of 24h DCV, 24h SCV, 24h SSD, 24h DSD levels predicting the occurrence of cognitive dysfunction in patients with ACI was more than 0.70, which had a certain predictive value, of which the joint detection value was the highest. Conclusion The blood pressure variability of ACI patients is closely related to the occurrence of cognitive dysfunction, which can effectively predict the occurrence of cognitive dysfunction.