In response to the increasing linguistic diversity in educational settings resulting from migration waves into the Global North, this study delves into the beliefs of secondary teachers regarding multilingualism within predominantly monolingual policy schools in Flanders, Belgium. Despite the recognized benefits of multilingual pedagogies, entrenched monolingual policies persist in many Western schools, posing challenges for teachers striving to navigate the linguistic repertoires of their students. Drawing on interviews with 18 teachers, including language and content teachers across three secondary schools, this research explores teachers' perspectives on the potential implementation of multilingual pedagogies in their classrooms. Findings reveal a nuanced landscape of beliefs, with teachers acknowledging the cognitive and emotional benefits of multilingualism while expressing concerns about maintaining control and promoting Dutch proficiency. Notably, minimal distinctions were observed between language and content teachers, indicating a shared optimism tempered by practical considerations. Our study highlights the need for nuanced understanding and support for multilingual pedagogies, underscoring the complex interplay of pedagogical and instructional beliefs in navigating language diversity. Ultimately, fostering inclusive and effective language education practices requires proactive efforts to address and accommodate teachers' beliefs, promoting professional development and dialogue around multilingualism in educational settings.