Introduction: Persons with haemophilia A (PwHA) with factor (F)VIII inhibitors, including children, have impaired health-related quality of life (HRQoL). The HAVEN 2 study (NCT027955767) of paediatric PwHA with FVIII inhibitors demonstrated that subcutaneous emicizumab prophylaxis resulted in low annualizedbleed rates. Aim: We assessed the impact of emicizumab prophylaxis on the HRQoL of children and their caregivers participating in HAVEN 2. Methods: Children aged 8-11 years self-reported HRQoL using the Haemophilia-Specific Quality of Life Assessment Instrument for Children and Adolescents Short Form (Haemo-QoL SF II). Caregivers of children aged 0-11 years completed the Adapted Inhibitor-Specific Quality of Life Assessment with Aspects of Caregiver Burden. All scores were transformed to a 0-100 scale, where lower scores reflect a better HRQoL. The number of missed days from school/day care and hospitalizations was also recorded. Results: In HAVEN 2 (n = 88), the median age was 6.5 years (range: 1-15 years); 85 participants were aged < 12 years and included in this analysis, and 34 participants were aged 8-11 years, thereby eligible to complete the Haemo-QoL SF II questionnaire. The mean (standard deviation, n) baseline Haemo-QoL SF II 'Total' score was 30.2 (14.9, 30), indicating moderate impairment; with emicizumab, mean score decreased by −9.62 (7.73, 17) points to 23.0 (13.93, 20) by Week 49. The most improved domains were 'Sports & School' and 'Physical Health'. Caregivers reported similar improvements. Conclusion: Prophylactic emicizumab is accompanied by substantial and sustained improvements in HRQoL of paediatric PwHA with FVIII inhibitors and their caregivers. K E Y W O R D S caregiver burden, children, emicizumab, haemophilia, health-related quality of life, inhibitors This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.