Background: Spinal cord injury (SCI) unsuccessful regeneration was due to glial scar development. It was a major obstacle to axonal restoration. Safe therapeutic intervention by the use of bone marrow derived stem cells (BMMSCs) transplantation applied in the present study could reduce spinal disability. Material and methods: Forty male albino rats were divided into four groups: GI: negative control (n = 10 rats); GII: positive control after SCI (n = 10 rats); GIII: SCI + BM − MSCs intravenous injected and GIV: SCI + BM − MSCs intra lesion injected (n = 10 rats in each group). The samples were taken from spinal cord tissues around the region of injury and were subjected to histological, immunohistochemical assessment. RNA extraction and real time PCR for detection of nerve regeneration and astrocyte response to the injury were also performed. Results: Clinical improvement occurred by the enhancement in the Basso, Beattie and Bresnahan (BBB) score after SCI. Histological examinations showed positive regenerative responses in GIV compared to GIII. Conclusion: BM-MSCs transplantation has a promising role in enhancing the microenvironment for nerve regeneration through stumbling the glial scaring formation and inflammatory response af-ter chronic spinal cord injury especially by using intra-lesion route injection. *