Pulmonary artery aneurysm (PAA) is a rare disorder that may be classified as congenital, acquired, or idiopathic, in the case of unclear etiology. When associated with severe idiopathic pulmonary arterial hypertension, such a case of PAA may present to the operating room as an indication for lung transplantation. In this article, we present such a case of a patient with a giant main and right PAA that underwent a double lung transplant. We describe the pathophysiology and natural course of this PAA and discuss the role of intraoperative transesophageal echocardiography in the management of patients with this rare diagnosis.