This study aimed to identify markers of early cognitive impairment after acute mild ischemic cerebrovascular disease. To further explore the relationship between neuroimaging markers of vascular and neurodegenerative injuries and post-stroke cognitive impairment, 86 patients with transient ischemic attack/acute mild ischemic stroke were recruited. Demographic information, clinical data, stroke scale scores (Modified Rankin Scale, National Institutes of Health Stroke Scale), and neuroimaging parameters (medial temporal lobe atrophy, global cortical atrophy, white matter hyperintensities, location and number of acute infarcts) were collected. All participants underwent neuropsychological evaluation at the time of discharge. The neurocognitive assessment was conducted using the Montreal Cognitive Assessment-Basic and Trail-Making Test A. It was found that low Montreal Cognitive Assessment-Basic scores were associated with global cortical atrophy and lower education levels. The completion time on the Trail-Making Test A was significantly correlated with medial temporal lobe atrophy and less education. It is concluded that global cortical atrophy and lower education levels can be used as rapid indicators of early cognitive impairment in patients after a transient ischemic attack and acute mild ischemic stroke. Medial temporal lobe atrophy also appears to be associated with mental processing speed in patients after a transient ischemic attack and acute mild ischemic stroke.