As quality of life (QoL) research is increasingly focusing on children and adolescents with haemophilia, the need for both age-appropriate and disease-specific assessment tools becomes apparent. Therefore, a set of questionnaires measuring QoL in children and adolescents with haemophilia was simultaneously developed in six languages within the European Haemo-QoL project (Haemophilia, 8, 2002, 47; Haemophilia, 10, 2004, 17). For implementation in larger studies and for use in daily clinical routine, a both short and psychometrically robust version of the questionnaire is needed. Using from the Haemo-QoL field study complete data sets of 306 children and adolescents (4-16 years) and their parents, a multivariate approach of item selection was applied to construct an eight-item instrument, the Haemo-QoL Index. The instrument is applicable to different age groups and represents the core content as well as the multidimensional structure of the original long versions. According to preliminary analyses, the index's psychometric performance concerning reliability and convergent validity is good. Further validation of the instrument's performance on a new and independent sample is needed.