Abstract Body (Do not enter title and authors here): Background: Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Within CVDs, cerebrovascular diseases (CeVDs) share risk factors with both stroke and dementia. Neuropathological lesions such as lacunar infarcts, hyaline arteriolosclerosis, and cerebral amyloid angiopathy are recognized contributors to cognitive decline. Yet, little is known about how the composition of carotid atherosclerotic plaques relates to these brain pathologies. This autopsy-based study investigates associations between carotid plaque components and cerebrovascular lesions relevant to dementia. Methods: We used data from the Biobank for Aging Studies at the University of São Paulo Medical School, with participants who were 50 or older at death, with a post-mortem interval under 24 hours, and an informant who had at least weekly contact with the individual, were eligible (n = 566). Carotid plaques were assessed histologically and quantified using the Atherosclerotic Plaque Analyzer software. Neuropathological evaluation followed internationally accepted protocols. Associations between plaque features and cerebrovascular lesions were tested using multivariable logistic regression models adjusted for sociodemographic and clinical variables. Results: Higher arterial obstruction (OR = 1.20, 95% CI 1.11–1.29) and IMT (OR = 1.08, 95% CI 1.01–1.15) were associated with increased LI risk. Similarly, HA was linked to greater stenosis (OR = 1.08, 95% CI 1.04–1.13), IMT (OR = 1.05, 95% CI 1.01–1.09), and plaque fibrosis. CAA showed no association but was related to necrosis in common carotid/bifurcation plaques (OR = 1.41, 95% CI 1.10–1.81) and lipid core in internal carotid segments (OR = 1.08, 95% CI 1.01–1.16). Stratified analyses revealed stronger associations in proximal carotid segments, suggesting location-dependent effects. Smooth muscle cell presence was protective against LI and HA, while plaque instability (necrosis, hemorrhage, or thrombus) increased HA risk. Conclusion: These findings demonstrate that carotid plaque composition and stenosis independently predict cerebrovascular injury, particularly LI and HA. This study provides a pathological association between atherosclerosis and cerebrovascular lesions, supporting targeted investigations to mitigate cognitive decline in aging populations.