Aspergillosis is a common fungal infection in immunocompromised patients undergoing chemotherapy. The incidence of invasive fungal infection in these patients has increased dramatically in recent years. We report a case of small-bowel infarction caused by Aspergillus in a 48-year-old man who was receiving chemotherapy for acute myeloid leukemia. On day 20 after the start of chemotherapy, right lower abdominal pain and rebound tenderness developed, with a high fever. A contrast-enhanced computed tomography scan showed a semicircular perfusion defect in the ileum. Thus, we performed partial resection of the ileum with primary anastomosis. Macroscopically, the ileum had mucosal ulcerations. Microscopically, there was transmural necrosis with microperforation and Aspergillus invading necrotic tissue and blood vessels. The patient had an uneventful postoperative course and was discharged 14 days after the procedure. Intestinal aspergillosis is rare and associated with high mortality. Thus, it should be considered in the differential diagnosis of neutropenic patients with sudden abdominal pain and fever.