Aneurysms of the pulmonary artery are proven to be a very rare entity. Association with structural cardiac anomalies, structural vascular anomalies, pulmonary hypertension, vasculitis, and infection has been noted. Surgical intervention of symptomatic aneurysms is recommended. A more detailed study of the natural history of these aneurysms is needed. Here, we report four cases of pulmonary artery aneurysms as well as a brief review of the literature existing on this subject. The first case is of a 41-year-old woman with the aneurysm located 1 cm distal to the pulmonary valve extending to the bifurcation of the main pulmonary artery. The second case is of a 76-year-old woman with a large aneurysm of the main pulmonary artery and the left pulmonary artery. The third case is of a 61-year-old woman with an aneurysm of the common pulmonary artery and right pulmonary artery. The fourth case is of a 28-year-old woman with a 5-cm symptomatic aneurysm extending from the valve up to the pulmonary bifurcation. Surgical excision and reconstruction was ordered for cases 1, 2, and 4.