Abstract: A method of obtaining Factor VIII which comprises(a) adding heparin to freshly obtained blood plasma collected into a calcium chelating anticoagulant or collecting blood plasma by plasma pheresis using heparin and a calcium chelating anticoagulant;(b) freezing the plasma;(c) resolubilizing the plasma;(d) isolating a cryoprecipitate from the plasma;(e) resolubilizing the cryoprecipiate;(f) adding a citrate saline heparin buffer to the resolubilized cryoprecipitate;(g) incubating the buffered, resolubilized cryoprecipitate at a temperature of from about 0.degree. to about 10.degree. C. for a time in excess of about one hour, whereby Factor VIII present in the cryoprecipitate is insolubilized using heparin precipitable cold insoluble globulin and the resulting Factor VIII rich precipitate also includes cold insoluble globulin;(h) separating the Factor VIII rich precipitate; and(i) isolating Factor VIII therefrom.