Contemporary developments in the management of chronic diseases such as diabetes and asthma offer possibilities for optimal control, but patients increasingly need to take on responsibilities for self care. Health professionals require comprehensive assessments of outcome that include data reflecting patients' perceptions of their disorder and its management. Disease-specific, patient-centered questionnaires for evaluation of adults' health-related quality of life are available for diabetes and asthma. Little progress is evident in relation to pediatric instruments. This paper describes the development of such an instrument for measurement of 8- to 11-year-olds' perceptions of their asthma--the CAQ-B Psychometric characteristics of the CAQ-B are reported: principal axis factor analysis resulted in the derivation of four subscales reflecting children's perceptions of both active and passive aspects of living with asthma, together with their perceptions of its severity and any associated distress. Preliminary explorations with CAQ-B included comparisons of parents', doctors', and children's ratings of severity; comparisons of data from asthmatic and nonasthmatic children; comparisons of data from boys and girls.