This non-interventional study will prospectively collect detailed, high-quality documentation of bleeds, HRQoL, and safety in patients with hemophilia A with or without FVIII inhibitors treated according to local routine clinical practice (receiving FVIII replacement or bypassing agents as either episodic or prophylactic treatment). Actual patients will be enrolled from routine clinical practice in this observational study.

Inclusion Criteria:

• Cohort A: Patients greater than or equal to (>/=) 12 years of age at time of informed consent
• Cohort A: Diagnosis of congenital hemophilia A of any severity and documented history of high-titer inhibitor (that is, >/= 5 Bethesda units [BU])
• Cohort B: Pediatric patients less than (<) 12 years of age
• Cohort B: Diagnosis of congenital hemophilia A of any severity and documented history of high-titer inhibitor (that is, >/=5 BU)
• Cohort C: Patients >/=12 years of age
• Cohort C: Diagnosis of congenital hemophilia A and FVIII activity <1 percent (%)
• Cohort C: No prior history of a positive inhibitor against FVIII

Exclusion Criteria:

• Prior RO5534262 (not applicable if patient agrees that prior RO5534262 will preclude participation in a future investigational RO5534262 study)
• Bleeding disorder other than congenital hemophilia A
• Ongoing (or planned during the study) immune tolerance induction therapy with FVIII or FVIII prophylaxis if currently/previously exposed to an inhibitor
• Previous or concomitant thromboembolic disease
• Known human immunodeficiency virus (HIV) infection with cluster of differentiation (CD) 4 count <200 cells per microliter (cells/mcL)

Patients with hemophilia A with or without inhibitors against FVIII under standard-of-care treatment are to be enrolled.