Purpose: To report an uncommon case of chimney stent-graft migration in the aortic arch. Case Report: A 29-year-old man presented with chronic left arm hyposthenia after late displacement and thrombosis of a left subclavian artery (LSA) chimney graft that migrated retrogradely into the innominate artery 2 years after deployment. The self-expanding LSA chimney was placed during a redo procedure to repair a pseudoaneurysm and type I endoleak after an index emergency thoracic endovascular aortic repair for traumatic aortic rupture 1 year earlier. The patient was successfully treated in an elective procedure via a median sternotomy, with arch aortotomy under circulatory arrest to remove the proximal end of the thrombosed chimney graft from the ostium of the innominate trunk. Three months later, a left carotid-to-subclavian bypass was performed to restore flow to the left arm. Conclusion: Migration of the proximal end of an overly long chimney graft that moved freely in the aortic arch exposed the patient to a high risk of stroke and death. Because of the high-risk situation, open repair under circulatory arrest was elected to remove the proximal end of the chimney graft, with no major complications.