We report a case of spinal artery aneurysm, secondary to the coarctation of aorta, who presented with initial signs of transverse myelopathy. A 45-year-old woman was admitted to the hospital because of quadriplegia. She had a history of subarachnoid hemorrhage traced to unknown origin. Physical examination revealed hypertension of upper limbs, but any artery of the lower limbs was not palpable. On neurological examination, she was alert, quadriplegic, and anesthetic below C4 level. Neck was stiff and meningeal signs were presented. The liquor was bloody. Myelography demonstrated complete block at C5-6. The right retrograde brachial angiography showed an aneurysm of cervical spinal artery. Digital subtraction angiography demonstrated a coarctation of the aorta. Coarctation of the aorta was considered to have caused spinal artery aneurysm, and is the first reported case in Japan.