 - Patients with diagnosis of haemophilia A, treated with KOGENATE BayerFS as their only source of FVIII, decision taken by the investigator to administer KOGENATE BayerFS. 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. 