Schwann cells are the main supportive cells in the peripheral nervous system having the potential to promote neurite growth in the central nervous system provided they reach sufficient cell purity (>95%) compared to oligodendrocytes. Schwanosis as a known post-traumatic phenomenon has a limited capacity to provide injured spinal cord with enough neuroplasticity. In this study autologous Schwann cells were surgically introduced within the medullary syrinx in 33 cases of chronic post-traumatic myelopathies. Thirty three cases of chronic spinal cord injuries (>2 years) visited on outpatient neurosurgical clinic of Brain And Spinal cord Injuries Repair research center (BASIR) were selected for treatment having Frankel grading A and B and informed consent for the procedure of autologous Schwann cell transplantation. The inclusion criteria were; age <50 years, no ferromagnetic metallic implant artifact on MRI, spinal cord lesion size less than 10 mm, non-atonic bladder on cystometrograpghic studies, competent muscles and nerves in the affected limbs as checked by electrodiagnostic study, and passing a course of six month rehabilitation and physical therapy. The neurological status was recorded just before surgery by ASIA and FIM grading scores. Autologous sural nerves were harvested from the lower limb as monitored care surgical procedure. The nerve was cleaned of epineurium and cut into pieces for cell culture. The cell viability and purity was ensured prior to transplantation. The level of the intramedullary syrinx was defined on high resolution pre-operative MRI. The corresponding spinal level was ascertained by intraoperative imaging. Intra-peratve neuronavigation was employed to ascertain the intramedullary bubble position if necessary. The operation was performed through a 3-cm incision and small hemilaminectomy and durotomy, The cell rich suspension was injected within the syrinx. Post-operatively, they received steroids and antibiotics for 1 day and discharged on the second day. The patients rested for two days in both prone and supine positions to promote even cell distribution within the syringeal wall. The patients were ambulated on the third day and rehabilitative therapy was begun after one week. The motor, sensory and sphincter status were assessed by force gauge, pain threshold and neurological level, and dry intervals respectively on a regular basis and recorded. Sexual function was recorded as a personal report of feelings, and appearance of psychogenic erections. All patients had a magnetic resonance imaging 3 month post-operatively.being clinically assessed at 3 month intervals up to one year Results: After at least 12-month follow-up period all patients were doing well without any new complaints. Transient headache and local and funicular pain were the most common complications. Control MRI did not reveal any neoplastic growth. Mean postoperative FRS differed significantly from the preoperative values (P<0.05). There were no cases of neurological worsening, infectious or viral complications. Paresthesia and tingling were the first sensations reported by the patients within the first week after surgery, followed by increased automatic activity. Thereafter, sensory level descended and motor function improved significantly when compared to pre-operative status. In the cervical lesions this happened in distal muscles while in thoracolumbar region proximal muscles showed improvement at the beginning. Discussion and Conclusion: Recent studies have declared that the microenvironment of the injured segment of the spinal cord is an obstacle for successful reparative process in the proximal and distal directions. The precise mechanism appears to be partly related to decreased c-AMP in the terminal neurites at the injury site. Possibly central myelin is the main culprit for neurite growth inhibition and collapse via decreased protein kinase activity. Peripheral myelin derived from Schwann cells on the other hand has a promotive effect on the neurite growth by inhibiting the NOGO receptors and increasing intracellular CAMP. The results of our study show that the procedure of intramedullary cell transplantation has been safe during the 12 month follow-up period. Also it has promoted the sensory and motor status of the patients. The bladder and bowel functions also show improvement as well as sexual function. The tissue employed is harvested from a sterile surgical wound and autologous; therefore the chance for bacterial infection, blood borne viral infections, and graft rejection is minimal without necessity of immunosuppressive therapy. The maturity of the employed tissue and avoidance of mutagens in the tissue culture protocols nearly obviated the possibility of in situ tumorigenesis. Although the establishment of the effectiveness of cell therapy for treatment of spinal cord injuries requires larger series and trials with prolonged follow-up, preliminary results seem to be promising for the treatment of this malady.