Since the pathogenesis of hemolytic uremic syndrome (HUS) has not been fully understood, it is difficult to establish a therapy protocol for HUS. Until now, there have been no effective treatments of HUS, evaluated by prospective controlled studies. Progress in the management of acute renal failure has improved the prognosis of HUS. Recently, the effectiveness of plasma infusion has been considered to be doubtful. Antiplatelet therapy and vitamin E administration may be recommended to treat typical HUS without severe complications. In addition to these treatments, plasma exchange using fresh plasma or fresh frozen plasma is recommended to treat HUS in the adult, atypical HUS and typical HUS with severe complications in childhood, considering the poor prognosis in these conditions.