The last two decades have seen the implementation of numerous different bilingual programmes across Spain. This has resulted in many children having free access to bilingual education in the country for the first time. However, the reduced time frame has resulted in policy and implementation far outreaching results-based research. This has direct implications on the quality of educational programmes. Currently there is no legislation that stipulates specific training in bilingual methodologies, despite significant bodies of research pointing to the need for training in Content and Language Integrated Learning (CLIL). Furthermore, STEAM subjects are commonly included in these bilingual programmes through primary and secondary education and are therefore disproportionally affected. In this context, this study aims to determine the perceptions of bilingual teachers towards their training, preparation, and praxis in a bilingual programme. Data collection took place over five years, in a bilingual primary school in Madrid, through two validated questionnaires. Results are in line with existing literature and indicate a need for improved training in methodology. All teachers agreed there was an additional workload and that the use of CLIL methodologies in class had helped their pupils learn more effectively.