Complex, area-based initiatives are a widely adopted policy response to problems of health inequalities and social exclusion in industrialized countries such as the UK and the US.This article explores the problems of evaluating such initiatives in a context of rapid national and local policy change by drawing on the Children's Fund, a UK government initiative that established local partnerships in each English local authority to promote children's social inclusion. It is suggested that independent local evaluations commissioned by the partnerships have had limited influence on programme design and implementation, and indeed have been highly contested in their use.The importance of dialogic engagement between evaluators and stakeholders is highlighted.