Primary pulmonary artery sarcoma classically presents with symptoms and findings suggestive of acute pulmonary artery occlusion. An angiocentric mass or the finding of spindling neoplasm on needle biopsy should suggest this neoplasm. The rare unilateral location in the present case permitted resection by pneumonectomy. An endarterectomy technique was used to extract loosely adherent tumor-thrombus from the more proximal portions of the left pulmonary artery.