OBJECTIVETo report a new manifestation of the rare connective tissue disorder arterial tortuosity syndrome in the absence of skin and soft-tissue abnormalities and with bilateral, giant fusiform intracranial aneurysms.DESIGNCase report.SETTINGUniversity teaching hospital.PATIENTA 67-year-old man with a history of hypertension presented to medical attention after a syncopal episode. Imaging revealed incidental, bilateral, giant fusiform intracranial aneurysms of the internal carotid artery at their junction of the circle of Willis. There was also aneurysmal dilatation of the left main coronary artery ectasia and aneurysmal dilation of the aorta and bilateral iliac arteries, suggestive of arterial tortuosity syndrome.RESULTSThe patient's syncope was attributed to transient complete heart block for which a permanent pacemaker was placed. The patient started taking aspirin for stroke prevention and losartan potassium for blood pressure control.CONCLUSIONSTo our knowledge, we present the first case of arterial tortuosity syndrome with marked bilateral intracranial artery dilation in the absence of concurrent skin and soft tissue abnormalities. Workup may include systemic vascular imaging to characterize the extent of disease. Antiplatelet therapy can be used for stroke prevention by reducing the risk of clot formation in ectatic vessels with altered hemodynamics and subsequent embolism. Losartan is known to inhibit transforming growth factor β signaling and may be a specific modulator of disease expression in this syndrome.