Congenital, spinal, epidural cysts are rare causes of transverse or radicular spinal lesions. Usually these cysts are located in the thoracal region, are oblong-shaped, and extend over several segments dorsally to the cord. Frequently, they cause no symptoms for years. They are fairly accessible to diagnostics by modern neuro-imaging methods. We report on a 15 year old girl with paraparesis, which showed a slow progression over two years, short-term remissions, and finally impairment of bladder function. Myelogram, computer-assisted tomography and nuclear magnetic resonance tomography showed a large space-occupying mass from D8 to L1 epidural and dorsal of the myelon. Operation disclosed an epidural cyst from D10 to L2. Histologically, the removed material was classified as a meningeal cyst. Post-operatively the girl's condition improved under intensive physio-therapy. For the diagnosis of this spinal dysrhapic disorder CT scanning after intrathecal application of contrast medium and magnetic resonance imaging were most valuable.