A 67-year-old man complained of a burning pain and weakness of bilateral feet after contusion of the left lumbar region. Skin as well as bone dystrophy and disturbance of bladder function were not seen, but low skin temperature was observed in the left lower leg. Glove anesthesia was seen on bilateral feet. Patellar tendon reflex was accentuated but Achilles tendon reflex was diminished, and bilateral Babinski sign was positive. Compression of the spinal cord or spinal root nerve was not noticed by MRI, myelography and myelo-CT (from cervical to lumbar level). We suspected the complex regional pain syndrome type I, and performed sympathetic blockade, but burning pain was not relieved. We looked for spinal tumor, myelitis, collagen disease, vitamin deficiency and malignancy but could not find out any disorder. However, the patient had neuropathic sign in electromyogram, and high anti-HTLV-I antibody titers in blood serum (8192x) and cerebrospinal fluid (256x). We diagnosed this case as HTLV I-associated myelopathy (HAM). He developed, so called, HTLV I-associated pneumonia at 74 years of age. We suggest that HAM may rarely accompany a burning pain and neuropathy (not myelopathy) as main symptoms. The present case suggests that a patient with HAM may develop HTLV I-associated pneumonia during its process; indicating a new concept of this very rare disease.