As part of the reform of English children's services, children's trust pathfinders were launched in 2003 by the British government to promote greater inter-agency co-operation between children's services and professionals. This paper reports on early findings from a multi-method, longitudinal national evaluation of the implementation and impact of all 35 children's trust pathfinders. Using data from a 2004 survey of 35 children's trusts managers and in-depth interviews with 107 professionals conducted in 2005, results show strong endorsement of an integrated children's service vision. However, arrangements for co-operation on governance and strategic developments were more advanced than for procedural or frontline professional practice. In this transitional period, professionals were negotiating a balance between targeted and universal service provision and, concurrently, establishing the scope of formal strategic partnership bodies (including local safeguarding children boards) with potentially overlapping remits. Copyright © 2006 John Wiley & Sons, Ltd.