The purpose of the study is to evaluate the effectiveness of Elocta compared to conventional factor products in the prophylactic treatment of patients with haemophilia A over a 24-month prospective period. Data will also be collected for a 12 month retrospective period.

Inclusion Criteria:

• Male patients with a diagnosis of haemophilia A
• Received prophylactic treatment with a factor product for management of haemophilia A in the 12 months prior to enrolment
• At enrolment prescribed prophylactic treatment with Elocta or conventional factor product regardless of participation in the study
• Having at least 12 months documented pre-study treatment data regarding prophylactic treatment prescriptions and bleeding episodes prior to the baseline visit
• Signed and dated informed consent provided by the patient or the patient's legally acceptable representative for patients under the legal age before any study-related activities are undertaken. Assent should be obtained from paediatric patients according to local regulations

Exclusion Criteria:

• Enrolment in a concurrent clinical interventional study involving intake of an investigational medicinal product (IMP), within 1 year prior to enrolment
• Previously treated with commercially available extended half-life products other than Elocta
• Presence of factor VIII inhibitors (≥0.60 Bethesda Unit [BU]/mL ) at the latest available inhibitor test using the Nijmegen modified Bethesda assay

Male patients with a diagnosis of haemophilia A prescribed prophylactic treatment with Elocta or conventional factor product