The content and international evidence for the Incredible Years programmes for children and teachers are described. This is followed by a description of their introduction in Wales from initial pilot trials to a Welsh Government funded Wales wide training initiative. Building on earlier work to support parents in Wales, the paper describes how these evidence based programmes for teachers and children, developed in a different country, were introduced and evaluated in Wales and how the demonstration of effectiveness has resulted in subsequent roll out that has been supported by local Authorities and the Welsh Government.