Although the pulmonary artery is involved in many cases of Takayasu arteritis, few cases have been reported in which the pulmonary artery was initially involved. Two such cases are reported here. Both of these cases had been initially diagnosed as chronic pulmonary embolism. The importance of considering Takayasu arteritis in cases of chronic pulmonary arterial obstruction of unknown cause is emphasized. Bronchial-pulmonary artery communication and coronary-bronchial artery communication in Takayasu arteritis are also discussed.