Moschcowitz's syndrome is a rare condition with poor prognosis. It is characterized by a microangiopathic haemolytic anaemia associated with thrombocytopenia, neurological symptoms and renal involvement. The vascular lesions consist of hyaline microthrombi, predominantly made up of platelet aggregates, disseminated in the smaller vessels. The physiopathological mechanisms are still poorly understood and probably multiple. Recent studies have demonstrated abnormalities in the endothelial synthesis of prostacyclin, and in many cases the lack of a plasma factor has been held responsible for intravascular disseminated platelet aggregation. The latest therapeutic attempts suggest that the most effective treatment probably is fresh plasma transfusions associated or not with plasma exchanges.