Traumatic infraclinoidal aneurysms of the internal carotid artery are rare. They can occur after craniocerebral lesions and can lead to life-threatening haemorrhages from the nasopharyngeal space. Frequently it may take months after the accident before the patient experiences single or repeated rupture bleeding and is referred to acute treatment in an ENT ward. Angiography can confirm the diagnosis and is mandatory to clarify the question of collateral flow in cerebral circulation. In case of local inoperability combined with the need for a ligature of the internal carotid artery, the protective application of an extra-intracranial microvascular anastomosis is an improved safeguard against postoperative deficits. During the past five years five patients suffering from an infraclinoidal aneurysm of the carotid artery have been operated on successfully in this manner. Two of these patients suffered from a traumatic aneurysm; these two case reports are presented.