We describe an unusual case of invasive pulmonary aspergillosis (IPA) complicated by subclavian artery occlusion in a 32-year-old man with severe aplastic anemia, who underwent allogeneic stem cell transplantation. He was severely neutropenic after the conditioning for transplantation, but he had no history of fungal infection. Five days after the transplantation, he developed IPA in the left upper lung, complicated by left subclavian artery occlusion. Extensive chronic graft-versus-host disease, which required the administration of potent immunosuppressants for a long period of time, interfered with the resolution of the IPA.