Saphenous vein graft aneurysm is a rare complication of coronary artery bypass graft (CABG) surgery that is challenging to manage and is associated with catastrophic consequences. We present the case of a 72-year-old woman with prior CABG surgery who presented with chest pain and was found to have a giant saphenous vein graft pseudoaneurysm. Further evaluation revealed that a vein graft pseudoaneurysm was causing significant compression of the left atrium. The pseudoaneurysm was successfully excluded from the blood flow with a covered stent; however, despite intra-aortic balloon pump and supportive therapy, the patient succumbed to cardiogenic shock and sepsis.