(1) We evaluated efficacy of several treatments for HTLV-I-associated myelopathy (HAM) on the basis of our study on 254 HAM patients and of literature review. Improvement of motor disability more than fair response was obtained as follows: 82% in prednisolone, 69% in interferon-alpha, 92% in fosfomycin, 82% in high-dose vitamin C, 72% in blood purification therapy, 70% in heparin, 59% in salazosulfapyridine, 56% in thyrotropin-releasing hormone, 55% in erythromycin, 50% in mizoribine. (2) In the absence of clear guideline, the efficacy of zidovudine in the AIDS dementia complex has been demonstrated. There are also efficacy of amytriptylinein controlling HIV headache, corticosteroid in mononeuritis multiple and inflammatory myositis, hydrocortisone in autonomic neuropathy and plasmapheresis in distal sensory neuropathy respectively. Otherwise, it is emphasized that ddI, ddC and d4T have peripheral neuropathy as major, dose related side effect.