In response to the exponential growth in the prevalence of autism in Ireland and 95% of all children availing of the universal free pre-school scheme, AsIAm delivered a continuing professional development (CPD) programme, to 311 adult learners. The paper reports on a multi-method evaluation of the impact of the programme on early childhood teachers' capacity to effectively include and support autistic children. The findings underline the importance of government investment in lifelong learning and the potential of a focused CPD programme to transform both participants' professional lives and the experiences they provide for the children in early learning and care services. Recommendations for future policy development are also suggested.