BACKGROUND Spinal epidural hematomas usually occur under certain conditions; they rarely occur spontaneously. The prevalence of spontaneous spinal epidural hematoma is ~ 0.1 per 100,000, and the male-to-female ratio is approximately 1.4 to 1. Herein, we describe a rare case of spontaneous spinal epidural hematoma. METHODS A 63-year-old Taiwanese woman, with underlying hypertension, anemia, and a history of cardiovascular accident without sequela, was admitted to our emergency department with a chief complaint of sudden bilateral weakness in the lower limbs. Magnetic resonance imaging revealed a spontaneous epidural hematoma. The patient underwent emergency surgery to remove the epidural hematoma and laminectomy for decompression. The bilateral lower limb weakness was alleviated immediately after the surgery. CONCLUSIONS In patients with no risk factors related to spinal epidural hematoma, symptoms of bilateral lower limb weakness must be investigated carefully because this condition may occur spontaneously.