Background: A multitude of causes have been attributed to unilateral recurrent laryngeal nerve palsy. In the absence of a local or a regional cause for palsy, it is prudent to look into distant and rarer causes. Case Report: A 70-year-old male presented with the complaints of hoarseness of 3 months that was insidious in onset and progressive. Contrast enhanced computed tomography of neck and thorax showed left vocal cord palsy with silent thrombus in arch of aorta extending to ascending aorta. The results of cardiac auscultation and electrocardiography were normal. Conclusion: Cardiovascular causes have to be kept in mind, for they may lead to grave complications if missed when vocal cord palsy is the only presenting complaint. This underscores the importance of the knowledge of these rarer but sinister causes. Here we present a rare case of isolated left vocal cord palsy being the only presenting feature of a silent aortic arch thrombus.