The Irish language, despite being the first official language in Ireland, is an endangered minority language. It is spoken, as the daily language of communication, by less than 3% of the national population and only 27% of the Gaeltacht population. In education, two different Primary School Curriculum guidelines (one for Gaelscoileanna and Gaeltacht schools and one for national schools) reflect the different sociolinguistic roles that Irish plays within Irish society and the segregation existing between children of different linguistic backgrounds. Also, there is no language policy in Ireland for the teaching of foreign languages at primary level, which is in contrast to the support that the European Union gives to multilingualism from an early age. From a different perspective, at pre-service level, primary school teachers receive their training through the medium of English, which results in poor levels of Irish being acquired. Also, there is no training available for the teaching of foreign languages within the Bachelor of Education or the Professional Diploma in Education (primary level). The development of a combined language policy for primary education for English, Irish and foreign languages is a main component of this work. This thesis looks at the experience of Catalonia, where this challenge has already been overcome with regard to second language acquisition, and compares it with Ireland’s experience. In Catalonia, there is a long tradition of early immersion education in Catalan; the agenda has now moved to third language development through researching the most effective teaching methodologies. Consequently, this is a comparative study between Ireland and Catalonia based on two main research methods: firstly, a theoretical analysis of issues related to cognitive language acquisition and European and State policy regarding language status and language use; secondly, an empirical study (consisting of qualitative and quantitative data) of teacher attitudes on early trilingual education in primary schools in Ireland and Catalonia. Hence, we explore the proposition that Ireland requires an integrated national language policy that includes English, Irish and a foreign language in the Primary School Curriculum which is directed at the achievement of high levels of proficiency in the three languages by the end of compulsory education. The results of this study suggest the appropriateness of developing a trilingual education system for primary education in Ireland based on early total immersion in Irish and the teaching of an L3 as content subject (1st-4th class) and through Content and Language Integrated Learning (5th and 6th class). This needs to be accompanied by strong institutional support with a redesign of both the Primary School Curriculum and of the pre-service training of primary school teachers.