Thyroid hormone has been studied in cardiovascular disease but rarely in cerebrovascular disease (CVD). Recently, hypothyroidism has been suggested to be related to risk factors such as atherosclerosis but not directly to CVD. We reported a 52-year-old woman with acute ischemic stroke, and greatly improved general conditions after thyroid hormone replacement. Hypothyroidism is reported to be one of the causes of hypertension or elevated cholesterol levels, the established risk factors of CVD. Further studies of the possible association of thyroid hormone and CVD are warranted. Thyroid hormone might need to be surveyed in CVD patients especially if there are symptoms and signs of thyroid disorders.