BACKGROUND Asymptomatic, isolated cases of unilateral pulmonary artery atresia may present in adulthood with symptoms such as recurrent respiratory infections, dyspnea, hemoptysis, and pulmonary hypertension. Unlike previously reported patients that underwent surgical management for this pathology, the patient in this report had no chronic history of recurrent respiratory infections, dyspnea, or pulmonary hypertension, making a diagnosis prior to extensive imaging difficult. METHODS A 55-year-old male presented to our emergency department (ED) with a 3-day history of recurrent cough with 2-3 tablespoons of hemoptysis per episode, chills, and occasional wheezing. A computed tomography angiography (CTA) was performed, which identified a congenital absence of the left pulmonary artery and a right-sided aortic arch. Hypertrophied left intercostal and bronchial arteries were noted to be perfusing the left lung. V/Q scan confirmed a heterogeneous distribution of gas throughout both lung fields with 97% perfusion to the right lung, but no visualization of the left lung on the perfusion images. Given extensive collateral blood supply to the left lung, interventional radiology performed a GELFOAM® embolization of the hypertrophied left bronchial artery and two parasitized arteries from the left subclavian artery to minimize intra-operative blood loss. This was immediately followed by a left thoracotomy, pneumonectomy, intercostal muscle flap placement, and bronchoscopy. The procedure was 360 min long with a total of 1500 cc blood loss that was salvaged and re-infused. No additional blood products were administered. The patient remained intubated post-operatively and was transferred to the surgical intensive care unit. His postoperative course was complicated by troponin leak, rhabdomyolysis, delirium, and ileus, all of which resolved over time. He was discharged home on postoperative day seven and continues to do well one-year later. CONCLUSIONS The patient in this report presented with several episodes of isolated hemoptysis but unlike previously reported cases of unilateral pulmonary artery atresia, he had no history of recurrent respiratory infections, dyspnea, or pulmonary hypertension. Although unilateral pulmonary artery atresia is a rare diagnosis, in patients with unexplained, isolated hemoptysis, further examination of the vasculature may be warranted, and surgical management may be beneficial in appropriate, symptomatic patients.