A 67-year-old gentleman with a prior history of coronary artery disease and a four-vessel coronary artery bypass graft five years prior to admission, presented to the hospital complaining of a 12-day history of midsternal chest pain. A chest radiograph performed 18 months prior to this presentation revealed a normal cardiovascular silhouette and normal mediastinum. Upon presentation, a new chest radiograph revealed a wide mediastinum. A computed tomography done emergently revealed an aortic thrombus starting at superior mediastinum and large (6 cm) pseudoaneurysm in anterior mediastinum. An emergency angiogram revealed that the pseudoaneurysm to be emerging 2 cm below the innominate takeoff in the ascending aorta, which corresponded exactly to the prior CABG cannulation site. The patient underwent successful repair.