Ewing sarcoma (ES) infrequently affects the spine. Diagnosis is usually made several weeks following growing symptoms. In this report, we present the case of a child with ES localized at the upper thoracic level. ES was revealed by isolated acute complete paraplegia mimicking medullary stroke. The girl was operated for decompressive laminectomy and tumor removal. Afterwards, she received adjuvant therapy. Subsequently, the child showed a slow improvement of her leg sensitivity associated with a partial motor recovery. ES can affect the mobile spine. Acute symptomatology due to intratumoral hemorrhage and sudden spinal cord compression may suggest the diagnosis. Neurological outcomes following ES are generally poor.