OBJECTIVE: Spasticity has been reported to be one of the common complications in patients with spinal cord injury. The purposes of this study were to investigate the proper dosage, the therapeutic and undesirable effects of clonidine with combined used of baclofen for the management of spasticity. METHOD: A prospective study was performed for 17 patients with spinal cord injury who did not improve spasticity with 80 mg baclofen administration. The degree of spasticity was assessed in the more-affected knee by modified Ashworth scale, pendulum test at pre-treatment and at 7 days after receiving clonidine. We also investigated the complications and subjective satisfaction. RESULTS: Seven of 13 patients with spinal cord injury showed subjective improvement in spasticity. We found significant improvement in the relaxation index by pendulum test after administration of more than 0.3 mg of clonidine. There was no significant difference between the subgroups depending on the extent of spinal cord injury. We didn't find any serious complication in adjuvant clonidine therapy. CONCLUSION: Adjuvant clonidine therapy can be effective in spasticity of spinal cord injured patients without serious complication.