Acquired hemophilia A (AHA) is a rare bleeding disorder due to the development of specific autoantibodies against factor VIII. The anti-CD20 monoclonal antibody Rituximab has been proven to be effective in obtaining a long-term suppression of inhibitors of AHA, besides other immunosuppressive standard treatments. Here we describe a case of idiopathic AHA in a 60-year old man successfully treated with rituximab. He showed a complete clinical response with a normalization of clotting parameters after 5 weekly courses of rituximab given at a dose of 375 mg/sqm., but after stopping rituximab, an initial worsening of coagulation parameters induced the addition of 3 further courses. At present, the patient is in complete clinical and hematological remission after 200 days. This case confirms that Rituximab may be a safe and useful tool to treat AHA and, a prolonged administration can overcome the initial resistance. However, the precise position of this drug in the therapeutic strategy (first or second-line, alone or in combination with other drugs) remains to be established and warrants further investigation.