The last significant advance in the therapy of hemophilia B was the introduction of recombinant factor IX (FIX), ensuring an advanced level of safety from potential infectious contaminants of plasma-derived clotting factors. Since that time, recombinant DNA techniques have been applied in research to elucidate the role of FIX and its functional domains within coagulation. At the same time, recombinant DNA technology has been applied to engineer an expanding spectrum of novel FIX therapies that are now being translating into clinical trials. The experience with the existing recombinant FIX product is reviewed with a focus on the novel products and the potential to improve the quality of life for individuals with hemophilia B.