We report a case of spontaneous spinal epidural hematoma with spontaneous remission diagnosed by MRI on superacute stage. A 52-year-old man was admitted to our hospital because of severe shoulder-neck-back pain of acute onset. One hour after onset he had left hemiparesis and gradually became tetraparesis. He had no history of trauma, anticoagulant therapy, or a tendency to bleed. There was no abnormality in the laboratory data. CT scan of the head revealed no abnormality, but the scan of cervical region showed an abnormal high-density area in the left posterior region of spinal cord at C4-C7. MRI demonstrated an epidural mass lesion in the left posterior region of spinal cord at C3-Th3 compressing the left side of spinal cord posteriorly was iso-intensity on the T1-weighted image and high-intensity on the T2-weighted image. However, his motor function recovered almost completely without a slight motor weakness of left upper limb about two hours after onset spontaneously. He was initially treated with a corticosteroid agent, and he could walk next day after onset. After about 2 weeks of onset, MRI revealed a vanished epidural hematoma and no abnormal enhancement. After about 2 months of onset, spinal angiograms revealed no vascular anomaly. The mechanism of spontaneous recovery from tetraparesis is assumed that the spreading of hematoma in epidural space up- and downwards to the rostro-caudal direction results in decompression. MRI is useful to detect spinal epidural hematoma safely and accurately for its diagnosis. MRI is also proved to be an accurate and efficacious method for evaluation of its size, location, and extent in the spinal canal.