Hemophilia is an inherited bleeding disorder caused by deficiency of coagulation factor V111or factor 1X. This chapter provides detail guidelines for coagulation factor replacement therapy. The need to administer frequent infusions of clotting factor concentrates often necessitates use of central venous access devices, which may serve as source of infections. There is lot of interest in developing gene therapy for hemophilia. Much work remains in order to bring gene therapy to the forefront.