The objective of the present study was to correlate electroneuromyography (ENMG) and evoked potentials findings with clinical aspects and intrathecal synthesis of HTLV-I antibodies production on HTLV-I myelopathy (HAM). Patients were seropositive for HTLV-I by different assays and seronegative for HIV and VDRL. They had no other causes of myelopathy and peripheral neuropathy. Peripheral neuropathy was established in 34.3% of the cases by ENMG. Peripheral neuropathy was mostly asymmetric (82%), sensory motor (90%), axonal (54.5%) or of a mixed type (45.4%). In 63.6% of these cases related symptoms were observed. ABR was abnormal in one patient and the PRVEP in 28.5%, who were symptom-free. The SEP was abnormal in 85.7% of the cases, half of them presenting clinical complaints. In only 14% of the individuals with clinical manifestations, SEP was normal. In 28% of patients with abnormal SEP the ENMG disclosed a peripheral neuropathy.