BACKGROUND The aging of the population has become increasingly obvious in recent years, and the incidence of cerebral infarction has shown an increasing trend annually, with high death and disability rates. AIM To analyze the effects of infarct location and volume on cognitive dysfunction in elderly patients with acute insular cerebral infarction. METHODS Between January 2020 and December 2023, we treated 98 cases of elderly acute insula, patients with cerebral infarction in the cerebral infarction acute phase (3-4 weeks) and for the course of 6 months in Montreal Cognitive Assessment Scale (MoCA) for screening of cognition. Notably, 58 and 40 patients were placed in the cognitive impairment group and without-cognitive impairment group, respectively. In patients with cerebral infarction, magnetic resonance imaging was used to screen and clearly analyze the MoCA scores of two groups of patients with different infarctions, the relationship between the parts of the infarction volume, and analysis of acute insula cognitive disorder in elderly patients with cerebral infarction and the relationship between the two. RESULTS The number of patients with cognitive impairment in the basal ganglia and thalamus was significantly higher than that without cognitive impairment (P < 0.05). The total infarct volume in the cognitive impairment group was higher than that in the non-cognitive impairment group, and the difference was statistically significant (P < 0.05). The infarct volumes at different sites in the cognitive impairment group was higher than in the non-cognitive impairment group (P < 0.05). In the cognitive impairment group, the infarct volumes in the basal ganglia, thalamus, and mixed lesions were negatively correlated with the total MoCA score, with correlation coefficients of -0.67, -0.73, and -0.77, respectively. CONCLUSION In elderly patients with acute insular infarction, infarction in the basal ganglia, thalamus, and mixed lesions were more likely to lead to cognitive dysfunction than in other areas, and patients with large infarct volumes were more likely to develop cognitive dysfunction. The infarct volume in the basal ganglia, thalamus, and mixed lesions was significantly negatively correlated with the MoCA score.