Reports of intracerebral hemorrhage (ICH) in patients with hemophilia B are relatively rare. We describe the first clinical results of the use of a monoclonal antibody purified factor IX (FIX) concentrate (Mononine) after an ICH and the long-term outcome of prophylaxis with this product to prevent recurrences. A 44-year-old male with severe hemophilia B was referred to our department because of nausea, vomiting, left lower limb hemiplegia, and left arm paresis. Computed tomography (CT) revealed a right frontal intraparenchymal bleed. The patient was treated with replacement therapy with FIX for 40 days. Computed tomography scans performed on day 40 after the event showed complete disappearance of the cerebral hematoma from the parenchymal tissue. Subsequently, the patient received 25.6 IU/kg(-1) of FIX twice a week. At the 48-month follow-up visit, no more major or minor bleeding events had occurred. Long-term prophylaxis after ICH is recommended.