Report on the immediate results of the use of ACTH in 4 cases of achylic demyelinating neuropathy. This treatment is justified by the possible allergic pathogenesis of the primary demyelinating processes. Dayly dosis of 12.5 mgm of corticotropin were given by continuous drip method, without any other associated drug which could interfere in the results. These were estimated on a semi-quantitative basis and evidenced slight beneficial effects of the hormone, which averaged 28.8 per cent. The accurate evaluation of the effects of corticotropin in subacute combined degeneration of the cord demands larger experience, based on greater number of cases and follow up of the patients, as well as the comparative study of such effects and the results obtained with classic treatment (liver extract, folic acid and vitamin B12).