Pulmonary artery dissections typically occur at the site of a pulmonary artery aneurysm associated with pulmonary hypertension or connective tissue disease. Dyspnea on exertion, retrosternal chest pain, central cyanosis, and sudden hemodynamic decompensation are the four main clinical signs and symptoms associated with a pulmonary artery dissection. Diagnosis of a pulmonary artery dissection frequently occurs postmortem, as many of these patients experience sudden death when the main pulmonary artery dissects into the pericardium, causing acute cardiac tamponade. Pulmonary artery dissection has been diagnosed in living patients using transthoracic echocardiogram, computed tomography (CT) scanning, magnetic resonance imaging (MRI), and angiography. Surgery is curative. Emergency physicians should consider the diagnosis of pulmonary artery dissection in patients presenting with either retrosternal chest pain, dyspnea on exertion, central cyanosis, or sudden hemodynamic decompensation and who have a past medical history of pulmonary hypertension, pulmonary artery surgery, or a disease causing chronic inflammation of myocardial or vascular tissue.