Based on the treatment with corticotrofin and corticosteroids of 518 patients admited at the "Clínica Neurológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo", in the period of 1952 to 1967, the authors performed a critical evaluation of the results obtained in several diseases of the nervous system: demyelinating diseases, polyradiculitis (Landry-Guillain-Barré syndrome), Sydenham's chorea, sabacute combined degeneration, hypsarrhytmia, myasthenia gravis, polymiositis, tuberculous meningitis and neurocysticercosis. ACTH or corticotrofin were employed intravenously or intramuscularly and the steroids were given orally or parenterally. The results with adrenal steroids or ACTH treatment were analysed under the treatment and preventive aspects. Concerning this aspect the analysis hás been limited, to tuberculous meningitis and neurocistycercosis cases. The evaluation of the therapeutic effects was based on clinical criterion and, when necessary, has been subordinated to an evolutive study concerning complementary examinations. Only immediate results based on general conditions of the patients at hospitalar discharge were reported. The authors conclude: 1. The corticotrofin and/or corticosteroids are used with favorable results in the treatment of several nervous system diseases as a therapeutic method as well as prophylactically. 2. Generally the results are difficult to evaluate and some times they depend on the nature and evolution of the disease and also on the period in which the treatment was established. 3. Regarding the therapeutic methods, the acute immunoallergic diseases or neuropathies with cyclical evolution those with a tendency to a progressive worsening and those with paroxystic manifestations responded in a better way to hormonal therapy. Some diseases which use to have an evolution with exacerbations and whose nature seems to be related to immunological factors also responded in a favorable way to ACTH and/or corticosteroids. 4. Consequently, better results were obtained in Sydenham's chorea, polyradiculitis, neurological complications of vaccination, in whooping-cough, epidemic parotiditis and eruptive fevers, in paroxysm crisis and cerebral dysrhytmia of hypsarrhytmia and in myasthenia gravis. In decreasing order regarding hormonal therapeutic benefits the authors point out multiple sclerosis and other primary demyelinating diseases. The small number of cases has not allowed a definite conclusion regarding polymiositis. Concerning primary demyelinating diseases the best results have been obtained when the treatment was employed during the first acute demyelinizating period of the disease, becoming less efficient on further exacerbations. Subacute combined degenation has been the neuropathy with less benefits regarding the hormonal treatment. 5. In sub-acute or chronic meningitis there were no good apparent results, but in recent cases in which the specific medication has been associated to ACTH or corticosteroids the effect has been excellent. 6. In neurocysticercosis the results generally have been favorable, justifying extensive use of hormones as preventive therapeutic in this disease. 7. With a criterious use and necessary precaution ACTH and corticosteroids have a significative low incidence of complications that, however, have been always severe. 8. With those restrictions, the treatment by hormones constitutes a precious weapon in neurological therapy. Even in those unfavorable cases, frequently the hormones represent the only available method and even the minor results obtained will justify its use. In some cases of dramatic evolution the use of ACTH and/or corticosteroids becomes almost imperative.