This article provides an overview of the role that interdisciplinarity plays in the Spanish education system. With this aim, we first describe the main conception of the term "interdisciplinarity" in texts written in Spanish, including other terms that have similar meaning. Then we review the role of interdisciplinarity in the Spanish curriculum at different levels of education, focusing fundamentally on compulsory education. This serves as the basis from which later to analyze Spanish research on interdisciplinarity. Finally, through results of this research and some examples of interdisciplinary school practices, we extract conclusions about the role of interdisciplinarity in teaching practices in the classroom.