There is a real need to promote integrated thinking within education in a globalised world whose problems are increasingly complex and interdependent every day. Integrated STEAM education has become one of the most relevant approaches within educational activities that integrate various disciplines. However, teachers often encounter difficulties with its implementation, due to its complexity. The aim of this study is to investigate perceptions of interdisciplinary integration among trainee teachers after the implementation of an iSTEAM+CLIL co-teaching proposal through a two-phase quasi-experimental pre-post study. The results pointed to an improvement in the levels of disciplinary integration that students perceived before and after the intervention. There was also some improvement in the level presented after the second intervention when teachers worked in ways that were more integrated than after the first intervention. Further action is therefore needed in this respect to encourage teacher training and to facilitate the implementation of this interdisciplinary approach in integrated teaching.
