This paper describes the American Academy of Pediatrics' program to develop several condition-specific measures to assess the functional status and well-being of children with chronic conditions. The development of a measure for children between 5 and 12 years of age with asthma serves as a template for the development of measures for other conditions and is the focus of this paper. The processes followed in the drafting of content, refinement, and pilot testing of the measure are discussed in this paper. The domains addressed in the asthma measure include physical symptoms; the child's physical activity; the child's social activity; the family's social activity; the emotional impact on the child; the emotional impact on the family; and health care utilization. Each domain is represented by a subscale in the measure. Content for individual items within subscales was established by conducting focus groups with parents and physicians and by reviewing the literature. The measure was tested through an in-depth cognitive interview process and pilot tested by administering the measure to 95 parents of children with mild, moderate, and severe asthma. Five of the seven subscales had acceptable internal consistency reliability as measured by coefficient alpha. Construct validity was shown for some scales by significantly different scores for children with mildly versus moderately severe asthma.