Background Carotid plaque is an important early predictive signal of clinical carotid atherosclerosis, the association between homocysteine (Hcy) and carotid plaque is well recognized, however, the correlation between Hcy and carotid plaque in postmenopausal middle-aged women is not established. Objective To analyze the impact of Hcy within the normal reference range on the risk of carotid plaque in postmenopausal middle-aged women and determine the risk threshold. Methods A total of 1 465 postmenopausal women (Hcy