Thoracic endovascular aortic repair (TEVAR) is currently the treatment of choice for thoracic aortic disease. In select cases, the TEVAR stent must occlude the left subclavian artery. This is usually well tolerated, but the subclavian steal syndrome (SCSS) may occur. Vertebrobasilar insufficiency can cause headaches, but reports of headache as the only symptom of SCSS are very rare. Thus, this may be under-recognised. To increase the awareness of this complication we describe the course of a patient who developed chronic intermittent headaches after intentional occlusion of the left subclavian artery with a TEVAR stent. Revascularisation may be required to prevent adverse neurological outcomes from SCSS. Some authors recommend prophylactic revascularisation whenever the left subclavian artery is sacrificed during TEVAR. However, transposition or bypass of this artery is not without risk and mild symptoms, such as secondary headache, can be fully controlled with conservative measures that reduce steal pathophysiology.