Abstract: Objective To explore the correlation between apathy and cognitive function in patients with cerebral small vessel disease (CSVD). Methods A total of 306 patients who were diagnosed with CSVD in Department of Neurology, the First Affiliated Hospital of Baotou Medical College, Inner Mongolia University of Science and Technology from April 2023 to August 2024 were continuously included. According to the Modified Apathy Evaluation Scale (MAES) scores, the patients were divided into two groups: apathy (MAES>14 points, n=131) and non-apathy (MAES≤14 points, n=175). Their cognitive function was evaluated by Montreal Cognitive Assessment (MoCA) scale. Their clinical data and cognitive function scores were analyzed. The correlation between MAES scores and cognitire function in CSVD patients was evaluated. Results The apathy group showed increases in age, male ratio, and percentages of smoking history, diabetes, hypertension, and cerebrovascular disease history, compared with the non-apathy group (P<0.05). Their MoCA scores, including those for visuospatial and executive function, naming, attention, language, abstraction, delayed recall, orientation and years of education, were lower than the apathy group (P<0.05). The MAES score in CSVD patients was negatively correlated with MoCA score, visuospatial and executive function, naming, attention, language, abstraction, delayed recall, and orientation (all P<0.001). Furthermore, MoCA scores for visuospatial and executive function (OR=0.656, 95% CI: 0.464-0.926, P=0.017), attention (OR=0.609, 95% CI: 0.422-0.879, P=0.008), and delayed recall (OR=0.591, 95% CI: 0.433-0.806, P=0.001) were identified as independent risk factors for apathy in CSVD patients. Conclusions Compared with non-apathy patients, CSVD patients with apathy show significant differences in cognitive function. The more severe the cognitive impairment, the higher the degree of apathy.