Abstract-This study outlines the development and evaluation of a structural equation model for establishing the consequences of haemophilia. The hereditary disorder is characterized by a high tendency to haemorrhages, with recurrent bleeding mto the joints causing irreversible joint damage. The model is, in general, an attempt to answer the following questions: what is the effect of haemophilia on the wellbeing (i.e. satisfaction, health, somatic complaints and self-esteem) of patients and what is the additional or mediating role of other individual characteristics in this pathway? Disease severity, joint impairment and disability are defined äs antecedents of well-being and the mediating roles of appraisal (i.e. the personal evaluation of the disease), health beliefs (i.e. locus of control), psychological characteristics (i.e. anxiety, anger, depression and optimism) and social Support are investigated. Psychological variables turned out to be the strengest determinants of well-being and partly mediated the detrimental effect of disability on well-being. The role of appraisal remained somewhat unclear, äs no significant relationship was established between this personal evaluation of haemophilia and well-being. Nevertheless, appraisal very well reflected the level of disability. An internal locus of control and favourable psychological characteristics appeared to reduce the perceived seriousness of haemophilia. No evidence was found for social Support to act äs a mediator between disability and well-being. The perception of support did show moderately strong associations with psychological characteristics (i.e. anxiety and depression) and satisfaction ratings. The study merits further research on quantifying the relationships between clinical parameters and psychosocial outcomes in patients with a chronic disease.