To evaluate long-term safety (primarily by recording adverse events including inhibitors), efficacy and patient acceptance of KOGENATE Bayer in home treatment either on prophylaxis or on demand.

To evaluate both safety and efficacy with respect to lot variability, in particular regarding lot-groups formulated with or without fix between.

Inclusion Criteria:

• Patients with severe haemophilia A (<2% FVIII baseline plasma levels) treated with KOGENATE Bayer as their only source of recombinant FVIII

Exclusion Criteria:

• Exclusion criteria must be read in conjunction with the product information (SmPC)

Patients with severe haemophilia A (<2% FVIII:C baseline level) treated with Kogenate Bayer as their only source of recombinant FVIII