Leadership development and the creation of school networks are two major strands of the government's reform agenda for education. This study examines the use of a senior team leadership programme as a vehicle for supporting school improvement across an Education Action Zone (EAZ). The study shows that senior team effectiveness is a critical variable relating to impact in schools and that teamwork skills cannot be taken for granted. In reviewing the lessons from the initiative the study suggests how leadership programmes might be used strategically within school networks to foster well-rooted change.