OBJECTIVES: To identify theoretical and methodological challenges to valuing children's health for cost-utility or benefit-cost analysis. METHODS: We reviewed the most common approaches, quality-adjusted life years and willingness-to-pay values, for valuing health in economic evaluations and considered methodological and practical issues associated with measuring child health using each framework. RESULTS: The review of theoretical and practical challenges suggests that both areas pose challenges to valuing child health. Practical challenges include elicitation issues and the consideration of household effects of child illness. One challenge is the inability of young children to value changes in health directly and the potential biases associated with using proxy respondents. The most appropriate elicitation method will vary by age of the child under consideration. Another key challenge arises from the status of children not as independent economic actors, but as being dependent on others for care and decision making. In addition, illness in children may also affect parent/caregiver quality-of-life further complicating the measurement of value associated with the change in a child's health status. From a theoretical perspective, “value of a child's health” has not yet been adequately defined if one accepts that many children are insufficiently mature to have informed, considered preferences over health states. CONCLUSION: Recommendations for moving the field forward in valuing child health for economic evaluations will vary by age; a “one size fits all” approach does not readily fit. Future research should focus on minimizing bias from proxy respondents, consideration of a family or household-based approach to valuing health effects, and development of generic instruments for children with age-appropriate domains.