Traumatic aneurysms are rare lesions. They differ markedly from saccular aneurysms in their clinical presentation and therapy. Early diagnosis of traumatic aneurysms is usually difficult. A 52-year-old female presented with massive epistaxis and ear bleeding caused by a traffic accident. On admission, her consciousness level was 7 points of the Glasgow coma scale. Computed tomography revealed hematoma in the sphenoid sinus and fractures in the right petrous bone, and right acute subdural hematoma. 7 years after trauma, she presented ear bleeding. Cerebral angiography showed a giant traumatic aneurysm at the petrous segment of the right internal carotid artery. Test occlusion of the right internal carotid artery was performed and was well tolerated without development of focal neurological deficits, so the right internal carotid artery was occluded using endovascular techniques. We recommend that more attention be paid to the traumatic aneurysm of the C4 to C5 portion when patients with skull base fracture are diagnosed.