There is a need to understand the practicality, validity and reliability of using utility measures with children and adolescents. We designed a pilot study in order to help guide the selection of an appropriate health-related quality-of-life (HRQoL) questionnaire for adolescents to be used in the context of a large randomised controlled trial (RCT) of family therapy versus standard treatment for adolescents aged 11-17 years. The pilot study was carried out on a school sample of adolescents in the same age range as the RCT. Adolescents were asked to fill in three HRQoL questionnaires: the standard EQ-5D, the licensed Health Utilities Index HUI, and the child-friendly version of the standard EQ-5D: the EQ-5D for youth (EQ-5D-Y). This report explores the problems with the language and concepts embodied within those HRQoL questionnaires and open discussion regarding how we can value the health of adolescents for cost-utility analysis in a larger study.