The objective in this study is collecting post-marketing information on the safety and efficacy of Kovaltry under the routine clinical practice.

This company-sponsored study is a single-arm, prospective, observational study in hemophilia A patients administered Kovaltry. 200 cases will be planned to be registered as safety analysis set in three-year period. Within 200 cases, 50 cases less than 12 years old will be planned to be registered. Target population are all hemophilia A patients. The treatment should be performed based on the product label in Japan. The standard observation period is two years.

Inclusion Criteria:

• Male and female hemophilia A patients.
• Patients for whom the decision to treat with Kovaltry was determined prior to enrollment in the study.

Exclusion Criteria:

• Patients participating in an investigational program with interventions outside of routine clinical practice.
• Patients with an additional diagnosis of any bleeding/coagulation disorder other than hemophilia A

Male and female hemophilia A patients are registered after the decision for treatment with Kovaltry has been made by the investigator. Both 'on demand' and 'prophylaxis' treatment are included.