A 68-year-old woman presented to the emergency department for evaluation of bilateral leg weakness. On admission, she had paraparesis with incomplete sensory deficit. Magnetic resonance (MR) imaging of the thoracolumbar spine revealed spontaneous spinal epidural hematoma (SSEH) compressing the spinal cord. The patient was taken to the operating room for urgent surgical decompression and evacuation of the SSEH. After the surgery, she woke up with complete paraplegia. Postoperative MR imaging showed the spinal cord was edematous, with minimal remnant hematoma. MR imaging after 1 month clearly showed anterior spinal artery thrombosis. No significant neurological improvement occurred during the 3-month follow up. Surgeons should consider the possibility of this devastating complication before aggressive and early surgical intervention in a patient with SSEH causing cord compression and neurological deficit.