Introduction. - High dose steroids and intravenous immunoglobulins are the gold treatment of acute immune thrombocytopenic purpura, before splenectomy for severe and refractory forms of the disease. Authors report two cases of severe acute refractory immune thombocytopenia with a dramatic response to plasma exchanges. Exegesis. - The first case was an idiopathic form, complicated by hemorragic peritoneal effusion. After failure of steroids, intravenous immunoglobulins and splenectomy and 2 courses of rituximab, plasmapheresis normalized in 3 days platelet count. In the second observation, ITP was associated to systemic lupus with antiphospholipids antibodies and multivisceral failure, despite steroids and intravenous immunoglobulins. After 3 plasma exchanges, platelet count was normalized, and the patient is under remission after 24 months follow-up. Conclusion. - Plasmapheresis must be evaluated as an emergency treatment in refractory forms of acute immune thrombocytopenic purpura. (c) 2005 Elsevier SAS. Tous droits reserves.