INTRODUCTION: Floating thrombus in an aberrant right subclavian artery is a rare cause of peripheral arterial embolic events. CASE REPORT: We report a 45-year-old woman who presented with an ischemia of the right superior limb from embolic event. The diagnosis of mobile thrombus in an aberrant right subclavian artery was obtained with transoesophageal echocardiography and computed tomography. After three weeks of oral anticoagulant therapy, there was no significant resolution of the thrombus, and a surgical treatment was performed to prevent further embolization. The surgical procedure consisted of thrombectomy and reimplantation of the aberrant right subclavian artery to the right carotid artery. Postoperative recovery was uneventful. CONCLUSION: This case report illustrates that transoesophageal echography and computed tomography are useful to detect mobile thrombus of the thoracic aorta and is warranted in any embolic event in young patients.