Research about health is concerned with physical and mental well-being, illness and injury. Directly or indirectly, health relates to almost every aspect of early childhood. This article reviews the enormous range of research available, examining the aims and purposes of the studies, their methods and findings and the ways in which childhood and child—adult relationships are conceptualized. In particular, this article is concerned with whether the evidence available arises from studies concerned with cost-effectiveness or with equity and the re-distribution of wealth and resources.