Purpose To investigate the relationship between carotid arterial calcium score (CarACS) and silent cerebrovascular lesions in patients with obstructive sleep apnea (OSA). Materials and Methods This study involved retrospective evaluation of 60 OSA patients who underwent both upper airway CT and brain MRI. Using polysomnography, several indicators, including apnea index (AI), were used to evaluate the relationship between OSA and silent cerebrovascular lesions. The CarACS was quantified on CT imaging using the modified Agatston method. Silent cerebrovascular lesions were evaluated on brain MRI by grading periventricular hyperintensity (PVH). Various clinical characteristics, including age, were analyzed in each patient. Results The number of patients per PVH grade 0, 1, 2, 3, and 4 was 26 (43.3%), 14 (23.3%), 14 (23.3%), 4 (6.7%), and 2 (3.3%), respectively. The mean age, hypertension, smoking status, AI, and CarACS were significantly different among PVH groups (Ps < 0.05). In univariate analysis, the presence of carotid arterial calcification (β = 0.483, p < 0.01), CarACS (β = 0.482, p < 0.01), and age (β = 0.360, p < 0.01) showed a significant association with PVH grade. The mean AI and lowest O2 saturation had statistically weak associations with PVH grade (β = 0.267, p < 0.01; β =-0.219, p < 0.14, respectively). In multivariate analysis, CarACS was the only factor affecting PVH