We present an adult female patient who developed irreversible paraplegia and areflexia four days post intrathecal chemotherapy with methotrexate, cytosine arabinoside and hydrocortisone. On magnetic resonance imaging (MRI) of the lumbar spine, diffuse gadolinium enhancement of the anterior spinal nerve roots (ventral roots) was detected. Methylprednisolone was intravenously administered at a daily dose of 30mg/kg for three days. Despite this treatment, flaccid weakness in the lower extremities and urinary retention persisted. Following consolidation chemotherapy, no improvement in neurologic status was noted. Six months later, a follow-up MRI revealed severe atrophy of the thoracic spinal cord.