Abstract Bilateral Congenital agenesis of the internal carotid artery is a very rare anomaly. Intracranial circulation in the involved internal carotid artery territory is maintained by collateral circulation from the contralateral internal carotid artery through the anterior communicating artery and from the vertebrobasilar system through the posterior communicating artery. People with this abnormality asymptomatic for many years. However, patients may also present with pulsatile tinnitus, headache or blurred vision, or rarely with ischemic stroke or subarachnoid hemorrhage. Diagnosis is usually incidental with the performance of carotid artery Doppler ultrasonography or cervical/cranial magnetic resonance imaging owing to other symptoms. We report on a case of bilateral internal carotid artery agenesis with pulsatile tinnitus lasting 5 years,other clinical presentation and imaging findings. Keywords: Agenesis, Internal carotid artery