Previous reports have suggested a correlation between autoimmunity and abortive axonal regeneration in mammalian CNS. In this study we investigated the effects of immunosuppressive treatment with Cyclosporine A (CyA) (2.5-5 mg/kg/day) on axonal regeneration after complete spinal transection in rats. Partial recovery of function was observed 30 days after surgery in rats treated with CyA, with the presence of incomplete spontaneous locomotion and a positive contact placing reaction. Restoration of somatosensory evoked potentials and positive retrograde fluorescent tracing were also observed. CyA reduced the autoimmune reaction which targeted components of the axons. These results provide further evidence of the role played by autoimmunity in blocking regeneration of fibre tracts in mammalian CNS.