 - Patients with diagnosis of hemophilia A, independent of age, treated with KOGENATE FS as their only source of FVIII, decision taken by the investigator to administer KOGENATE FS. For pretreated patients with more than 100 exposure days an inhibitor assessment within three months prior to enrollment should be available; for pretreated patients with less than 100 exposure days an inhibitor assessment at baseline should be available. 