A 20-yr-old hemophiliac with an anti-Factor VIII antibody level of 8 units/ml of plasma was hospitalized with a subdural hematoma and progressive neurologic deterioration. He underwent craniotomy and evacuation of the hematoma, and was discharged with minimal neurologic deficit. His successful management required two exchange transfusions utilizing an Aminco continuous flow Celltrifuge, immunosuppression with cyclophosphamide and corticosteroids, ε-aminocaproic acid (EACA), and large doses of AHG concentrates. Complications included hemolysis and platelet dysfunction due to hyperfibrinogenemia, leukopenia, and Gram negative sepsis. The cost of the patient’s 6½ wk hospitalization was $58,751, of which $38,039 was for AHG concentrates.