Pulmonary artery sarcoma (PAS) is a rare tumor that is often detected at an advanced stage, when disease is so widespread that a radical surgical procedure is no longer indicated. Therefore, less invasive biopsy techniques are required to establish a definitive preoperative diagnosis. Endobronchial ultrasound (EBUS) is useful for producing real-time images of both lymph nodes and the interior of pulmonary arteries adjacent to the bronchi. We report a case with masslike lesions in the pulmonary artery that were observed by EBUS and from which tissue was obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) to establish a diagnosis of PAS.