Although pulmonary artery aneurysms are a rare vascular anomaly, they are seen in a wide variety of conditions, such as congenital heart disease, infection, trauma, pulmonary hypertension, cystic medial necrosis and generalized vasculitis. To our knowledge, mycotic aneurysms caused by pulmonary actinomycosis have not been reported in the radiologic literature. Herein, a case of pulmonary actinomycosis complicated by mycotic aneurysm is presented. On CT scans, this case showed focal aneurysmal dilatation of a peripheral pulmonary artery within necrotizing pneumonia of the right lower lobe, which was successfully treated with transcatheter embolization using wire coils.