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 sub-acute infection, most commonly seen in patients with altered local defense system from preexisting pulmonary disease of 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 chronic necrotizing pulmonary aspergillosis complicating pulmonary aneurysm is 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. Angioinvastion of aspergillus was revealed by pathology after operative removal of left upper lobe containing the pulmonary artery aneurysm. He was treated with itraconazole.