Quality of life (QoL) assessment in children with chronic health conditions and disabilities needs to be age-appropriate and address health-related as well as disease-specific concerns of children in a balanced way. The proposed DISABKIDS modular approach has tackled these challenges of international paediatric OoL research by providing modules that are on the one hand applicable for children of specific age groups and specific health conditions, and on the hand can be applied across different subgroups. The DISABKIDS questionnaires have been developed within a European cross-cultural multi-centre study in order to be able to compare different conditions across health care systems from different countries and in order to be able to conduct multinational clinical studies. The DISABKIDS groups used a simultaneous approach towards cross-cultural instrument development that ensures the cross-cultural applicability of the measures. The current handbook describes all relevant user information (e.g. psychometrics or reference data), necessary for applying the DISABKIDS questionnaires. The authors:Silke Schmidt, Corinna Petersen, Holger Mühlan, Marie Claude Simeoni, David Debensason, Ute Thyen, Esther Müller-Godeffroy, Athanasios Vidalis, John Tsanakas, Elpis Hatziagorou, Paraskevi Karagianni, Hendrik Koop-mann, Rolanda Baars, John Chaplin, Mick Power, Clare Atherton, Peter Hoare, Michael Quittan, Othmar Schuhfried and Monika BullingerTHE DISABKIDS Group Europe