Spontaneous epidural hematomas (SEHs) of the lumbar spine are rare. The pathogenesis is not entirely clear, but several reports have suggested that bleeding originating in the venous epidural plexus is the cause. This is the second report of a SEH thought to be the result of facet joint hemorrhage with no previous synovial cyst formation. A magnetic resonance image revealed a mass beginning in the left epidural space and continuing through to the left L5-S1 facet joint. Surgically, the epidural hematoma, which was covered by a very thin translucent membrane, was visualized directly. A histopathological examination revealed the wall of the epidural hematoma to be composed of very thin fibrous connective tissue with no synovium lining. The purpose of this study was to report a case of an epidural hematoma originated from lumbar facet joint, diagnosed by radiological examination, and to present a review of the subject literature.