Background. Takayasu arteritis (TA) is an idiopathic chronic inflammatory arteritis that affects the large blood vessels. Pulmonary involvement was considered an uncommon manifestation of the disease and spontaneous pneumothorax has not been previously described in association with TA. Case. We report a 13-year-old female who had TA complicated by spontaneous pneumothorax during treatment. She was admitted to the hospital reporting difficulty standing from a squatting position and inability to walk without support. She had been diagnosed with dilate cardiomyopathy four years ago and cardiac functions had deteriorated over time. Catheter angiography revealed diffuse narrowing of the abdominal aorta. In magnetic resonance angiography, total-subtotal occlusion of the infrarenal abdominal aorta in a 2 cm area and subtotal occlusion of the left renal artery were detected without pulmonary artery involvement. Methotrexate, azathioprine, and prednisolone were administered. Tension pneumothorax developed on the left side while she was on prednisolone treatment. Conclusion. To our knowledge, this is the first case of spontaneous pneumothorax associated with TA to be reported in the literature.