Noniatrogenic traumatic extracranial internal carotid artery dissections were encountered in six patients (five men and one woman) 31 to 62 years old. All but one had overt cerebral ischemia manifest by paresis (three), sensory deficits (three), aphasia (three), or amaurosis fugax (two), One patient had an asymptomatic carotid artery bruit. Cerebral arteriography established the diagnosis in all cases. Internal carotid artery impingement between the mandible and transverse processes of the second and third cervical vertebrae, or undue stretching over these vertebral structures, were the most likely primary mechanisms of injury. Secondary complications, a result of distal thromboembolism, were evident in two patients. Direct cerebral revascularization, staged internal carotid artery constriction and ligation, as well as intensive nonoperative therapy were valid therapeutic options. There were no deaths. Treatment relieved transient ischemic symptoms or arrested progression of established neurologic deficits in each case. In select patients, early surgical intervention may lessen attending neurologic sequelae.