Haemophilia, an inherited x-linked bleeding disorder, is a rare disease with comparable prevalence worldwide, which leads to early disability if untreated, and which, if treated via substitution of blood clotting factor, is associated with high treatment costs. Recent research has focused on bio-psychosocial consequences of treatment from the patient's perspective, in order to identify new treatment approaches, to quantify the patient benefit, and to compare haemophilia care across countries. For this, generic and disease-specific instruments have been developed and are currently being used in studies. The present paper describes clinical aspects of haemophilia as well as the assessment of quality of life and proceeds to introduce two recent studies on quality of life of children and adolescents with haemophilia in Europe. The HAEMO-QoL study investigated the quality of life of 339 children with haemophilia age 4 and above from six European countries. A total of 1,424 patients from 21 European countries participated in the ESCHQoL study, among these were 444 children aged 4 and above years. In both studies clinical data, information about health care and psychosocial determinants such as coping, life satisfaction and social support were assessed. Significant differences in quality of life between countries were found. Psychosocial determinants were associated with quality of life. Current analyses suggest that important determinants for quality of life are availability of factor concentrate from the clinical side and social support from the psychosocial side. The difference in quality of life across countries is a future major health-political challenge.