Differences between children and adults have both technical and ethical implications for the design, interpretation and employment of economic analyses of health-related programmes. Even though policy makers increasingly turn to economic analyses to inform decisions about resource allocation, pertinent child-adult differences have received fragmented discussion in leading methodological references. Key areas warranting attention include: the ways in which a child's distinctive biology modifies the cost and effectiveness of healthcare interventions; challenges in assessing utilities for infants and young children given their limited but developing cognitive capacity; how a child's age, dependency and disability affect the selection of the appropriate time horizon and scope of the analysis; whether a child's non-wage earning productivity should be incorporated into analyses, and if so, what metric to use; what principles of equity policy makers should employ in using economic evaluations to choose between child- and adult-focused interventions; and whether special protective measures should be introduced to secure the rights and interests of children who cannot advocate for themselves.