Spontaneous spinal epidural hematoma (SSEH) is a neurosurgical emergency that requires prompt diagnosis and treatment. We report a 24-year-old woman who presented with acute onset of paralysis in both lower limbs and sensory disturbance below the fourth-thoracic dermatome. Spinal magnetic resonance image (MRI) revealed an intraspinal, extradural mass is extending from the fifth to the seventh thoracic vertebrae with compression of the spinal cord. Laminectomy of the T5 to T7 vertebrae was performed 12 h after onset. During the procedure, an epidural hematoma with hypervascularization and an abnormal vascular network were observed grossly on the dorsal dural surface. Postoperative angiography and MRI revealed complete resolution of the hematoma and no evidence of residual vascular lesion in the intra- or extra-dural region. At 6-month follow-up, the patient had regained full muscle power and sensation in the lower limbs. There was no evidence of urinary or stool incontinence. The patient had a history of remaining seated for prolonged periods of time, which may have elevated the spinal venous return pressure, resulting in spontaneous hemorrhage due to rupture of the spinal epidural arteriovenous fistula. This case report shows that patients with SSEH can have excellent neurologic outcomes if the condition is treated early with decompressive laminectomy.