OBJECTIVES: Evaluation of cognitive status is not performed routinely in the acute stroke setting. This study aimed to evaluate the frequency of early cognitive impairment in patients with minor ischemic stroke, analyze the factors associated with early cognitive impairment, and assess functional outcomes. METHODS: In this prospective study, 112 consecutive patients with acute minor ischemic stroke were enrolled. Neuroimages were assessed for semiquantitative evaluation of brain atrophy and small vessel disease (SVD) markers. Cognitive performance was measured within 5 days of onset using Montreal Cognitive Assessment (MoCA) scores. Functional outcome analyses were adjusted for demographic variables, premorbid cognitive status, education level, vascular risk factors, neuroimaging characteristics, stroke severity, and MoCA scores. RESULTS: The median MoCA score was 22, and 63% of patients had cognitive impairment. Factors independently associated with cognitive impairment were education (odds ratios [OR], .79; confidence intervals [CI], .63-.99), smoking (OR, .26; 95%CI, .073-.89), and temporal horn atrophy (OR, 4.73; 95% CI, 1.66-13.49). Factors independently associated with poor functional outcome were total MoCA score (OR, .78; 95%CI, .62-.95) and the sum of 4 MoCA subscores (visuospatial/executive, attention, language, and orientation; OR, .72; 95%CI, .53-.92). The cutoff value of the sum of 4 MoCA subscores for predicting poor outcome was 13 points with 76.5% sensitivity and 81.1% specificity. CONCLUSIONS: Early cognitive impairment was common after minor ischemic stroke and was associated with preexisting temporal horn atrophy but not SVD markers. The sum of 4 MoCA subscores was useful in predicting the functional outcome.