Spontaneous dissection of the extracranial cervicocephalic arteries occurs most often in the internal carotid artery or vertebral artery. Spontaneous dissection of a common carotid artery is rare, with only nine cases having been reported. A 43-year-old man was hospitalized for sudden onset of motor aphasia and right arm weakness due to spontaneous dissection of a left common carotid artery; no sign of aortic disection was evident on aortogram. The most common causes of dissection of the common carotid artery are the extension of an aortic dissection and the complication in an angiogram with direct puncture; spontaneous dissection being very rare. We review the previous literature on this topic.