The objective of this study was to assess the reproducibility, construct validity, and responsiveness of the parent report version of the "How are you" (HAY), a quality of life questionnaire for children with a chronic disease. The reproducibility of the HAY was assessed by comparing the scores of two measurement cycles of children with stable asthma. Construct validity was evaluated by testing the differences between scores of the HAY of parents of children with and without asthma and by investigating the correlations between the HAY and instruments supposed to correlate with the HAY. Responsiveness was investigated in parents of children whose clinical status changed clinically relevant between two measurements. The HAY showed acceptable reproducibility. Also the HAY detected anticipated differences in quality of life between parents of asthmatic and healthy children. It furthermore showed acceptable ability to measure change in health status of children with asthma. The parent report version of the HAY shows acceptable reproducibility, supportive evidence for construct validity, and good responsiveness. The measurement of quality of life of asthmatic children and changes therein can truly rely on parental report.