A 71-year-old man was admitted to our hospital with disturbances of consciousness and right hemiparesis. Upon admission, brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) revealed an acute infarction in the area of the left middle cerebral artery, and a near-occlusion of the left internal carotid artery (ICA). A stent was placed in the ICA to maintain cerebral blood flow. Contrast-enhanced ultrasonography (CEUS) was performed on day 3, and a thrombus was identified along the inner surface of the stent. Intravenous heparin was continuously administered to decrease the size of the thrombus. A repeat CEUS on day 17 revealed a complete disappearance of the stent thrombus and stenosis. This case suggests that CEUS is a useful modality for the detection of stent thromboses, and for the evaluation of the effects of antithrombotic therapy.