Early childhood behavioural difficulties are becoming more prevalent (Collishaw et al., 2004) and increase the risk of poorer outcomes later in life, including academic difficulties, antisocial behaviour, criminality, and poor social adjustment. A growing body of literature highlights the importance of early intervention and prevention programmes, such as parent-training or school-based programmes, for the prevention and treatment of early childhood behavioural problems and promotion of child well-being. The Webster-Stratton Incredible Years (IY) Parent, Teacher and Child Training Series was designed for the early treatment and prevention of conduct disorders in childhood (Webster-Stratton & Hancock, 1998). The IY series comprises a suite of comprehensive, specially designed programmes, which target children aged 0-12 yrs, and their parents and teachers, with a view to improving social and emotional functioning and reducing or preventing emotional and behavioural problems. The implementation of the IY programme in several community-based agencies and schools in Ireland began in 2004 – spearheaded by Archways, the national co-ordinator of the IY programme in Ireland – as a means of preventing and treating emotional and behavioural difficulties in children.