Adrenoleukodystrophy is a genetically determined disorder inherited as an X-linked recessive trait due to the defective peroxisomal oxydation of very long chain fatty acids (VLCFA). It is hallmarked by demyelination of the central nervous system and adrenal insufficiency. Even though the studies concerning the molecular basis of the disease are in progress, the role of VLCFA in the demyelination is still unclear. In this paper we report the most recent knowledges about genetics, pathogenesis and treatment of this disorder. 117 cases have been recognized in Italy in the period 1985-1997, but many cases could be missing due to the heterogeneus clinical manifestations that vary from mild to very severe forms. To control the devastating course of this disease two therapeutic approaches are under evaluation: bone marrow transplantation and dietary treatment based on a mixture of glyceroyl trioleate and glyceroyl trierucate. Nevertheless this dietary treatment provides normalization of plasma VLCFA, no significant modification of the natural course of the disease has been demonstrated. For what concerns bone marrow transplantation, in recent years a more accurate selection of patients and donors has been giving favourable results, but some strict criteria should be respected.