A 52 year-old man was hospitalised for acute renal failure with thrombocytopenia and hemolytic anemia without oliguria. A haemolytic-uremic syndrome was diagnosed and prostacyclin infusion was started. Twenty-four hours later, the renal function improved as well as thrombocytopenia and anemia. Recovery occurred after 11 days of treatment. Haemolytic-uremic syndrome treatment is not well codified: plasmaphoresis, fresh frozen plasma, transfusions showed inconstant efficiency and data about prostacycline treatment are rare and often contradictory. Multicentric studies must be started in order to determine the precise benefit of this treatment.