Acquired hemophilia A is a rare but severe auto-immune bleeding disorder characterized by the presence of autoantibodies directed against clotting factor VIII. Acquired hemophilia A may be idiopathic or associated with several conditions, such as postpartum, autoimmune diseases, malignancies or drugs. The treatment modalities of bleeding episodes and eradication of the factor VIII auto-antibody depend on the titer of anti-factor VIII:C and may include desmopressin (DDAVP), prednisolone, prednisolone-cyclophosphamide, high dose intravenous gammaglobulin, FVIII-VWF concentrate and/or recombinant FVIIa (rFVIIa). In this study we report four cases of autoimmune factor VIII inhibitors (2 associated with autoimmune disorders, 2 idiopathic) demonstrating the heterogeneity of this disease from pathogenic, clinical, therapeutic and prognostic points of view.