Open access. Quality-Adjusted Life Years (QALYs) are often used to make judgements about the relative cost-effectiveness of competing interventions and require an understanding of the relationship between health and health-related quality of life (HRQOL) when measured in utility terms. There is a dearth of information in the literature concerning how childhood overweight is associated with quality of life when this is measured using utilities. This study explores how weight is associated with utility-based HRQOL in 5–6 year olds and examines the psychometric properties of a newly developed pediatric utility measure – the CHU9D instrument.