A spontaneous spinal epidural hematoma (SSEH) of the thoracic spine is a rare space-occupying disease that accompanied with severe axial pain in the spine. Because there is the possibility of a significant neurological injury such as paraplegia, SSEH requires careful diagnosis and management. A SSEH is mainly caused by a coagulating disorder or anticoagulant medication, while certain cases have shown that this disease is related with spinal inflammatory conditions. A SSEH tends to occur in patients who have risk factors for hemorrhage. However, the incidence of SSEH is quite low, and there are few domestic reports of a SSEH in young adults who are without the risk factors for hemorrhage. We encountered a 25 years old young male without a prior significant medical history and he was suffering from severe back pain and paraplegia due to a SSEH at the thoracic spine. The early diagnosis was made via MRI. We report here on a favorable clinical outcome that was achieved with immediate operative treatment, and we include a review of the relevant literature.