In the Republic of Ireland the vast majority of primary schools are owned and run by the Catholic and Protestant Churches. There is no parallel state system of education. Religious education in schools is doctrinal in nature and is permitted to permeate throughout the school curriculum. In addition, legislative provisions permit schools to discriminate in favour of co-religionists in admissions and employment policies. In the absence of the provision of non-religious schools, such a system of education violates the international right to freedom of religion or belief of minority-belief and non-belief pupils, parents and teachers. The aim of the paper is to examine the effectiveness of using international human rights law in working to bring about change in the place of religion in Irish schools. It traces attempts to bring the situation in Ireland to the attention of international human rights supervisory bodies and evaluates subsequent measures taken by the Irish authorities in response to international criticisms. It situates this analysis within a broader theoretical debate around the relationship between law and social change, and the way law may work to produce change and the factors that may limit that change.