A 35-year-old male diagnosed with a patent ductus arteriosus (PDA) 15 years prior to admission presented with shortness of breath, hoarseness, hemoptysis, and chest pain. A chest X-ray revealed a large mass in the left superior mediastinum (Fig. 1). A computed tomographic (CT) angiogram revealed a PDA aneurysm measuring 8.8 × 9.3 cm communicating with the pulmonary artery (PA) (Fig. 2): and compressing the left PA (Fig. 3). At the time of surgery, working through a left posterolateral thoracotomy, cardiopulmonary bypass was established via the distal thoracic aorta and main pulmonary artery. During a 44-minute period of circulatory arrest, the 1.5-cm fistula to the PA was closed with a Vascutek prosthetic patch (Terumo Cardiovascular Systems Corp., Ann Arbor, MI, USA) and continuity between the distal aortic arch and the descending aorta was restored with an 18-mm Vascutek tube graft (Terumo). The patient required reexploration for bleeding on the evening of surgery, but then had an uncomplicated postoperative course. Six months following surgery, his hoarseness is gone and his exercise tolerance has returned to normal.