OBJECTIVE: The transplantation of bone marrow cells into the injured spinal cord improves neurologic functions in experimental animals. However, it is unclear whether bone marrow cells can similarly improve the neurologic functions of complete spinal cord injury patients. To study their therapeutic effects in human spinal cord injury (SCI), we transplante autologous bone marrow cells into the SCI sites and administer granulocyte macrophage-colony stimulating factor (GM-CSF) in three complete SCI patients. METHODS: Bone marrow cell transplantation with GM-CSF administration was performed on two patients (patients1 and 2), wherein concentrated bone marrow cell pastes were injected into the injury area using a sterile 21 gauge fine needle. The total volume of bone marrow cells injected was 1.8ml (cell concentration 1.1X106/ul). Patient 3 was administered GM-CSF only. The follow up periods were 5 months (patient 1), 4 months (patient 2) and 6 months (patient 3). RESULTS: Sensory improvements were followed immediately after the operations. Sensory recovery in the sacral segment was noticed at 3 weeks (patient 1), 13 days (patient 2) and at 2 months (patient 3) postoperatively. Significant motor improvements were noticed at 3 months in patients 1 and 2, and at 4 months in patient 3. All three patients showed neurologic improvements at the last follow up 5, 4 and 6months respectively (Frankel grade C, AIS grade C). CONCLUSION: Treatment of SCI patients with autologous bone marrow cell transplantation and GM-CSF administration shows some beneficial effects during the early postoperative periods. However, long-term and more comprehensive clinical studies are required.