Because improving health is the ultimate goal of a health care system, the measurement of health outcomes in research is a logical and important goal for the evaluation of the impact of health services. Although health can be defined in various ways, here we employ a conceptualization that has several domains including longevity, disease, comfort, perceived well being, activity, achievement, and resilience. Given that health is such a broad concept, the difficult task for outcomes research is to provide the means of measuring it. As this brief summary of current work indicates, a number of approaches have been used in recent pediatric studies. Most focus on a small subset of health concerns. However, some studies have attempted to broaden the assessment of health outcome either by using multiple health measures or developing multidimensional instruments for measuring health. Care must be taken in evaluating the usefulness of any of the instruments until sufficient data are obtained as to their reliability and validity. Further work in this area is needed, particularly with regards to multidimensional approaches, which are beginning to provide a more sensitive and comprehensive means of assessing the impact of health services.