OBJECTIVES: Specific instruments are developed measuring HRQoL in children and adolescents. Currently, these instruments are not applicable in health economic studies as valuations for health states are lacking. The aim of the current study was to compare the psychometric properties of a generic child-specific and a generic preference based instrument in children and adolescents with ADHD. METHODS: A questionnaire survey was performed among parents with a child diagnosed with ADHD. Results on the proxy versions of the KIDSCREEN-10 and the EQ-5D were used to compare the constructs describing HRQoL of the instruments and their responsiveness to different health states. Principal Component Analaysis (PCA) with varimax rotation was used for identifying factors underlying the constructs of both instruments. A comparison was performed of the index scores on both instruments between respondents with different stimulant medication profiles and different comorbidity profiles using Student’s t-tests. Additionally, Cohen’s effect sizes were calculated for an indirect comparison of the instruments’ responsiveness and discriminating ability. RESULTS: Using the EQ-5D dimensions and the items of the KIDSCREEN -10 the PCA identified 5 separate components of HRQoL. A physical component and a mental component included a combination of EQ-5D dimensions and KIDSCREEN-10 items. No associations of the EQ-5D dimensions ‘self-care’ and ‘usual activities’ and KIDSCREEN-10 items was found. Additionally, no association was found of KIDSCREEN-10 items related to performance at school and satisfaction with free time activities and EQ-5D dimensions. Scores of both instruments differed significantly according to respondents’ treatment and comorbidity profile. Cohen’s effect sizes indicated comparable responsiveness and discriminative ability of the instruments. CONCLUSIONS: The results highlight that the two instruments measure different constructs of HRQoL. Despite this, the analyses showed comparable responsiveness to different health states and discriminative ability of the instruments. These results suggest that the KIDSCREEN and the EQ-5D are complementary instruments.