Primary pulmonary synovial sarcomas are extremely rare and account for less than 0.5% of all pulmonary malignancies. We present a case of a 45-year-old man with primary pulmonary synovial sarcomas in the right lower lobe of the lung. Contrast-enhanced computed tomography indicated 〞triple attenuation〞 (a soft-tissue attenuation with a well-enhanced solid portion and a cystic or necrotic portion). We confirmed the diagnosis of primary pulmonary synovial sarcoma by the histopathology and specific immunochemistry.