In this article, we describe a case of a surgically treated aneurysm of an aberrant right subclavian artery. The historical literature to date is summarized, as are the key concepts relative to the anatomy, embryology, diagnosis, and treatment of this uncommonly occurring entity. Although the topic might be expected to be of concern to only a few specialists, all physicians should be aware that a patient with an enlarging aneurysm of an aberrant subclavian artery may experience dyspnea, dysphagia, or sudden collapse from rupture as the initial manifestations. An asymptomatic patient may have a mediastinal mass detected by roentgenography. The diagnosis may be confirmed with computed tomography or magnetic resonance imaging. As with most aneurysms, surgical treatment is recommended, and the benefit-to-risk analysis depends on individual case factors.