A fibrinogen fraction separated from fresh frozen plasma by slow thawing at 2 C con-Factor VIII activity. The administration of t h i a material to six patients with hemophilia A resulted in partial to canplete coffcetion of their clotting defect. Clinical hanoetasis was d a t e d with th-Musiona Normal or higher than normal levels of Factor VIII were obwrved in one patient given this material in connection with surgery. Side effects did not occur during or after the adminisea. tion of the fraction. The preparation of thii material is simple and can be carried out as a routine procedure in blood banb processing large amounts of fresh frozen plasma.