Performance scales (i.e., Karnofsky), as they measure quality of life, have been used effectively as an integral part of repeated assessment of adult cancer patients for the last several years. An equally concise measure of performance has not been developed for children. The task of developing a scale to assess performance in infants, toddlers, school-age children, and adolescents is formidable, as the activity measured should be of equal merit at each age level. Although all childhood cancer patients could benefit from a simple-to-administer, rapid assessment, children with brain tumors have the greatest need for a repeated measure of performance. The goal, then, is to develop a simplified set of criteria that can be used for assessment of children with brain tumors during hospitalization, at the time of clinic visits, and/or at the time of diagnostic procedures when the patient is in a reasonable state of health. The assessment should be able to performed by nonprofessional persons.