ABSTRACT Language skills have demonstrated their significance in migration decisions; however, their role as a potential cause of immobility has been largely overlooked. In this paper, I first propose a theoretical model that seeks to explain decisions regarding mobility and immobility based on the instrumental returns generated by an individual's linguistic capital within a given opportunity structure. Secondly, I apply this model utilizing data from university and vocational training graduates in Spain. Leveraging its particularity as a case study, which encompasses five regions where a minority's co-official language is an integral part of ethnic identification and shares a similar institutional environment that encourages its use, I find that bilingualism is primarily linked to internal immobility. Simultaneously, it affects the direction of internal migration, since bilinguals are more inclined to relocate to areas with similar language conditions. Bilingualism also presents indirect effects. The results indicate that bilingualism influences international migration by facilitating the acquisition of a foreign language, which becomes increasingly attainable as the cost of language acquisition decreases, though the effect remains relatively small.