Currently, haemophilia care aims to provide the best possible quality of life for individuals living with this chronic disease. Many factors are known to influence treatment adherence, including treatment satisfaction. Health-related quality of life (HRQoL) and treatment satisfaction are, therefore, important outcomes in clinical trials and clinical practice. As individuals' perception of their well-being often differs from that of their physician, it is recommended that self-report instruments are used to assess patient-reported outcomes (PROs). The way that the impact of haemophilia is perceived by the patient and their family can be different, so it is important to assess how parents perceive the impact on their children. A series of PRO instruments have been developed, adapted to different age groups and parents of patients with haemophilia. To allow the instruments to be used internationally, culturally adapted and linguistically validated translations have been developed; some instruments have been translated into 61 languages. Here, we report the process used for cultural adaptation of the Haemo-QoL, Haem-A-QoL and Hemo-Sat into 28 languages. Equivalent concepts for 22 items that were difficult to adapt culturally for particular languages were identified and classed as semantic/conceptual (17 items), cultural (three items), idiomatic (one item), and grammatical (one item) problems. This has resulted in linguistically validated versions of these instruments, which can be used to assess HRQoL and treatment satisfaction in clinical trials and clinical practice. They will provide new insights into areas of haemophilia that remain poorly understood today.