A patient with ependymoma of filum terminale which was initially diagnosed as a lumbar disc herniation is presented. Compression of spinal nerve roots by an intradural mass due to ependymoma of filum terminale is a rare condition and should be kept in mind in the differential diagnosis of lumbar disc herniation. The normal postoperative appearance is important to recognize because a number of changes occur normally during the healing period. The differential diagnosis between an epidural scar or recurrent disc herniation and a spinal mass can usually be made with magnetic resonance imaging. In this study, the crucial role of magnetic resonance imaging with intravenous contrast in the differential diagnosis is also emphasized.