We present a 25-year-old male patient with neurofibromatosis type 1 (NF1). Thoracic intra-dural extra-medullary tumoral mass was excised gross-totally and the patient was referred to oncology unit. Histopathological diagnosis was malignant peripheral nerve sheath tumor (MPNST), a rare sarcoma with a dismal prognosis. Tumor recurred in its previous site with an adjacent apical mass in the left lung 7 weeks following initial surgery and repeat surgery was performed with complete removal of intra-dural tumor. We report the first patient with intra-dural MPNST localized proximal to conus medullaris; in upper thoracic spine. It must always be considered the possibility of a rare but a devastating tumor, MPNST beside schwannomas and neurofibromas in patients with NF1 when an intra-spinal mass is diagnosed.