We present the case of thoracic aortic aneurysm associated with the tuberculous pleural effusion. An 82-year-old woman underwent emergency stent graft under a diagnosis of dissecting thoracic aortic aneurysm. Preoperative computed tomography revealed right pleural effusion supposed to the hemothorax caused by the dissecting aneurysm. But, the effusion was sanguineous color fluid and it was determined to result from pulmonary tuberculosis. The medical team was exposed to the pulmonary tuberculosis; fortunately no one became infected. Physicians should be aware of the possibility of an infected aortic aneurysm and prepare for pathogen transmission.