Tackling health inequalities is moving up the policy agenda of richer societies like the UK, with governments looking for evidence to guide policy review and development. Observational studies of how childhood disadvantage compromises health in adulthood are an important part of the evidence base, but are largely inaccessible to the policy community. We develop a framework which captures the findings of these studies. Our framework highlights how disadvantage in childhood adversely affects both socio-economic circumstances and health in adulthood through a set of interlocking processes. Key among these are children's developmental health (their physical, cognitive and emotional development) and health behaviours, together with the associated educational and social trajectories. In breaking down the link between childhood disadvantage and adult health into its constituent elements, the framework provides a basis for understanding where and how policies can make a difference. The paper argues that the process of policy review and development needs to include both new programmes and the mainstream policies in which they are embedded.