Pulmonary aspergillosis is classified as a saprophytic, allergic, and invasive disease. Chronic necrotizing pulmonary aspergillosis is categorized as an invasive pulmonary aspergillosis. Most invasive pulmonary aspergillosis have acute and toxic clinical features but chronic necrotizing pulmonary aspergillosis is characterized by a subacute infection, most commonly seen in patients with altered local defense system from preexisting pulmonary disease or in mild immunocompromised patients. Pulmonary artery aneurysm due to this infection is termed as a mycotic aneurysm, etiology of which are tuberculosis, syphilis, bacteria and fungus. We report a case of chronic necrotizing pulmonary aspergillosis complicating pulmonary aneurysm in a 62 year-old man who was presented with cough, sputum, and fever. Chest radiographs showed a rapid, progressive cavitary lesion and pulmonary artery aneurysm. Angioinvasion of asper gillus was revealed by pathology after operative removal of left upper lobe containing the pulmonary artery aneurysm. He was treated with itraconazole.