The current report describes a female patient with Takayasu's arteritis who was hospitalized because of respiratory complaints and a ventilation-perfusion (V/P) scan demonstrating severe perfusion defects with normal ventilation. Her symptoms and V/P scan results were initially interpreted as massive pulmonary embolism, but a spiral computed tomography (CT) of the chest and a repeated lung scan indicated inflammatory involvement of the pulmonary artery accounting for the positive lung scan study. Review of her medical records from 17 years ago revealed that similar symptoms and a positive V/P scan were the initial features of her disease.