There is a theoretical and empirical tradition demonstrating the influence of the place of birth and self-identification in the shaping of language attitudes. But very few works analyse their joint effects. The main aim of this study is to analyse both the disaggregated and joint impact of these variables on the shaping of attitudes towards Catalan and Spanish languages in Catalonia. The sample consists of 309 adolescents (aged 14-16 years) coming from Ecuador, the rest of Latin America and Morocco. Both variables have an influence on attitudes towards Catalan separately, but when analysed jointly in the same explanatory model, self-identification outweighs place of birth. This is more evident among young people who develop the most and the least favourable attitudes. Furthermore, attitudes towards Spanish are only influenced by the place of birth, and by none of the variables in the case of those with the most and least favourable attitudes. These results open new lines for research and reflection on the process of construction of language attitudes and their role in a successful process of integration.