Outcome measures should include the patient's values and preferences (from the patient's perspective) in addition to performance ratings and physiologic states. Outcome measures can assess relationships between services and interventions and their end results, can clarify which therapies are worth providing and which therapies need more evidence about their effectiveness, and can measure the burdens of different disorders and interventions. Researchers recently have shown the feasibility of creating and using outcome measures for children with neurodevelopmental disorders. Clinicians may wish to familiarize themselves with the concepts of outcome measures and health-related quality of life in order to understand the rationale, utility, properties, and various types of outcome measures in order to select the most appropriate instruments that will best serve their patient populations. Ongoing research efforts are currently using such measures in children with central nervous system tumors, with neural tube defects, and of extremely low birthweight; in childhood and adolescent epilepsy; and in adolescents with headaches. (J Child Neurol 2000;15:775-780).