Objective To investigate the incidence rate of slowing of information processing speed （IPS） after ischemic stroke in young and middle-aged patients and related risk factors.Methods A total of 72 young and middle-aged patients in the acute stage of ischemic stroke who were hospitalized and diagnosed in Department of Neurology， The First People's Hospital of Zigong， from February 2021 to February 2023 were enrolled in this study. Related data were collected from all subjects， including demographic data， stroke data， vascular risk factors， imaging data， and laboratory examination data. Symbol Digit Modalities Test （SDMT）， Mini-Mental State Examination （MMSE）， and Montreal Cognitive Assessment （MoCA） were performed at 2 weeks after disease onset. According to the SDMT score， the subjects were divided into normal IPS group with 30 subjects and IPS slowing group with 42 subjects. A multivariate logistic regression analysis was used to investigate the risk factors for slowing of IPS.Results Among the subjects in this study， there were 47 males （65.3%） and 25 females （34.7%）， with a mean age of （54.28±6.14） years. Slowing of IPS was observed in 42 pationts （58.3%） at 2 weeks after disease onset. The multivariate logistic regression analysis showed that a relatively high NIHSS score before treatment （OR=2.381， 95%CI： 1.179-4.810， P<0.05）， the infarction site of the temporal lobe （OR=8.856， 95%CI： 1.433-54.748， P<0.05）， the infarction site of the lateral ventricle （OR=10.083， 95%CI： 1.526-52.614， P<0.05）， the infarction site of the insular lobe （OR=19.528， 95%CI： 1.354-281.677， P<0.05）， and a TOAST classification of arteriolar occlusion （OR=7.877， 95%CI： 1.526-40.656， P<0.05） were risk factors for slowing of IPS after ischemic stroke in young and middle-aged patients.Conclusions There is a relatively high incidence rate of slowing of IPS after ischemic stroke in young and middle-aged patients， and patients with a relatively high NIHSS score before treatment， the infarction site of the temporal lobe， the insular lobe or the lateral ventricle， and the TOAST classification of arteriolar occlusion tend to have a higher risk of slowing of IPS after stroke.