Spanish-English bilingual education programmes have spread widely in Spain in recent years. Although some evaluation research has already been conducted, the effects of this policy in terms of equity have received little attention. We analyse whether the supply of 'bilingual schools' is modulated by a set of factors that may affect the equality of opportunities available to students to access them. We study all primary schools in municipalities with more than 50,000 inhabitants in the region of Andalusia (n = 1,119). The odds that schools will offer this programme vary greatly across different catchment areas. They increase in catchment areas with higher incomes, when the school is private or subsidised-private, when it is closer to other schools, and when it is located in municipalities with younger populations and with a better situation in terms of unemployment. These imbalances in school supply produce significant inequalities in the structure of opportunities to attend bilingual education.