In this article we reflect on the learning of mathematics in bilingual settings from a social and a political perspective. In particular we highlight two concepts that are key to our work: language-as-resource and language-as-political. To do so, we draw on classroom data from students of Mexican origin in Tucson, USA, and students from Latin America in Barcelona, Spain. The language policies in our contexts share a message of privileging the language of instruction (English or Catalan) over other languages. Our analysis of the two sets of data points to differences in the mathematical participation of students on the basis of which language they use. We develop the argument that, even if languages other than Catalan and English are accepted and certain pedagogies may be close to a language-as-resource approach, the use of the students' languages is politically mediated in such a way that its pedagogical value (as a medium of communication and learning) is not always taken into account in the bilingual mathematics classroom.