A 67-year-old man was admitted with a saccular aneurysm of the abdominal aorta. Preoperative CT revealed cylindrical calcification of the abdominal aorta and the patent internal iliac arteries (IIAs). At the elective surgery, a cylinder-shaped and severely calcified intimal layer was found, and the lumbar arteries were totally occluded. Hypotension caused by the loose iliac clamp due to severe calcification continued for 15 minutes and long-time cross clamp was necessary. Monoparesis of the left lower extremity and dysuria occurred postoperatively. Spinal MRI revealed small infarction at the Th10 level. Symptoms improved and he could walk with a cane and within a few months no uninary catheter support was needed. Thoracic spinal cord infarction after abdominal aortic aneurysm (AAA) surgery and a severely calcified abdominal aorta indicated the importance of the blood flow in the IIA as the significant source of spinal blood supply. To prevent spinal cord injury (SCI) which is rare but significant complication of AAA surgery, understanding of the spinal blood supply, quick surgery, and complete revascularization of pelvic arteries are important.