We report a case of left common carotid artery dissection showing complete remission in the short term. A 48-year-old man presented a 1-week history of weakness in the right arm. Neurological findings revealed mild motor weakness of the right upper extremity. Magnetic resonance imaging (MRI) showed sporadic cerebral infarction and hemorrhagic infarction in the area of the left middle cerebral artery (MCA) and the posterior border zone. Computed tomographic angiography (CTA) revealed irregular stenosis with a smooth surface in the left common carotid artery and ultrasonography indicated an iso-echoic lesion in the same area. ECD-single-photon emission tomography (SPECT) showed low perfusion only in the infarcted territory. Conservative therapy using a free radical scavenger and aspirin was carried out and the patient displayed full neurological recovery. After a 3-week follow-up period, carotid angiography and CTA showed almost complete disappearance of the stenotic lesion.