Aim: 1) To assess the reliability and validity of the Swedish version of the Child Health Questionnaire (CHQ), 2) to determine the correlation between children's and parents’ responses to the CHQ, and 3) to describe and compare responses to the CHQ of four diagnostic groups. Methods: A total of 199 Swedish children aged 9–16 with diagnoses of asthma ( n =53), diabetes ( n =48), short stature ( n =51) and juvenile chronic arthritis (JCA, n =47) and their parents answered the CHQ and relevant validation instruments at a clinic check-up. Coefficient alphas were determined for all dimensions of the instrument, and all but four had acceptable to very good reliability (0.75–0.94). Results: Concerning construct validity, the CHQ correlated significantly with appropriate dimensions of the validation instruments. In general, there were significant correlations between the children's and parents’ responses. Comparisons between the diagnostic groups showed several significant differences. The short stature group had the highest quality of life and the JCA group the lowest. There were no sex differences, but children who had not reached puberty scored better on the dimensions of mental health and self-esteem. Conclusion: The Swedish version of the CHQ is a reliable and valid instrument. Furthermore, it is recommended to ask children themselves about their health-related quality of life.