This article analyses the effects of the language policy in Catalonia on the transition of immigrant students to upper secondary education in Barcelona by focusing on the language learning experiences and academic trajectories of two case-studies of Pakistani students whose communicative resources remain invisible despite the official celebration of linguistic diversity and which are not properly fostered to ensure their successful incorporation into post-compulsory education, despite their initial success and high aspirations. Although indicators of educational inequality show how young people born outside the EU experience an alarming disadvantage in comparison to their Spanish-born peers, little attention has been paid to factors related to the complex bilingual context of Catalonia. This article aims to shed light on the factors involved in the early school leaving of students from immigrant backgrounds, especially critical in the periods of transition, and the role played by the language policies, beliefs and ideology that they are exposed to.