The main pulmonary arteries are derived from the sixth aortic arch during intrauterine development. Proximal interruption of the right or left pulmonary artery is a rare anomaly, which may be accompanied by cardiovascular anomalies. We describe a 48-year-old man with interruption of left pulmonary artery with atrial septal defect and right side aortic arch. MRI is helpful in identifying the interruption of pulmonary artery, the collateral circulation, and the associated cardiovascular anomalies.