We report a 51-year-old man with human T lymphotropic virus type-1 (HTLV-1) associated myelopathy (HAM) manifested 10 months after renal transplantation. He had progressive spastic paralysis and neurogenic bladder for 10 years. HTLV-1 antibody are positive both serum and cerebral spinal fluid (CSF). Althoght HTLV-1 was not examined in the donor, it was suspected that the patient was infected by renal transplantation. After treatment of interferon-alpha (IFN-alpha), his motor function had improved and neopterin in CSF was decreased from 158 pmol/ml to 89 pmol/ml. This is a rare case of HAM after living renal transplantation. Cyclosporin and methylpredonisolone are used as immunosuppressants for preventing graft rejection. Time for developing HAM after renal transplantation was shorter than patients after cadaveric renal transplantation. More investigations are needed to clarify the mechanisms in the development of HAM associated with renal transplantation.