Post-infectious demyelinating disorders are uncommon. In the Hospital Pediatrico de la Misericordia de Santafé de Bogotá there were 14 cases in three years. The commonest age group was the new born, as is found in the literature. The infections involved in these neurological changes are probably viral, since at the time the patient is seen most symptoms have cleared up spontaneously. According to several authors, the viruses are most often found to be those of measles or mumps. Between the infection and the development of neurological symptoms there is an interval of approximately two weeks. The main clinical findings are motor changes such as hemiparesis, involvement of cranial nerves and alterations of consciousness. The aetiology is not completely clear. Firm diagnosis is made on histopathological studies which are seldom available. Usually neuroimaging techniques and cerebrospinal fluid analysis are the basis of the diagnosis. Computerized axial tomography and magnetic resonance are the most useful noninvasive techniques for assessing the involvement of the white matter, the extent and sites of the lesions. It is useful to know the classification of the demyelinating disorders so as to prescribe, the most suitable treatment and give the prognosis in each case. There is still no specific treatment for these disorders. Supportive measures, the control of epileptic crises and the prevention of complications are the main aims. This paper reviews the definition, classification, diagnosis and management of these disorders.