This article analyses the role of language in the intra- and intergenerational social mobility of Argentinean, Colombian and Moroccan immigrants in Catalonia, an officially bilingual society. It starts from the notion that the knowledge and use of and attachment to local languages are affected by the range and importance of opportunities for social mobility offered by the host society. Empirical evidence is based on 45 biographical interviews with members of first generation immigrant groups and their children (raised in Catalonia and currently living outside the family home). It is shown that the attitudes towards and use of the Catalan language depend on expectations and constraints with regard to upward social mobility. This article questions the causal relationship between languages spoken and job opportunities, postulated by means of the theory of human capital whereby language is only considered as a competitive advantage on the basis of its communicative value.