In the academic year of 2004-2005 the Spanish region of Madrid began to implement a bilingual educational programme in public schools. Currently, 45% of the public educational system (primary and secondary) participates in the bilingual programme of the Community of Madrid (hereinafter MBP). One of the objectives sought by this programme, but not the only one, is to make the study of a foreign language accessible to students from economically less favoured families (who have greater difficulty in meeting the cost of private language tutoring). Consequently, our study aims to analyse whether, as proposed, students from disadvantaged socioeconomic backgrounds effectively participate in the MBP. To comply with this objective, we estimate a model directed at identifying which factors influence the selection of a bilingual public school by families.