Education is one of the pillars of the welfare state in Spain, and one of the main ways of reducing inequalities and, potentially, integrating members of the immigrant population. Schools serve to promote social and cultural integration of foreign students and their families. Spain, although its history as a country of immigration has been short, has been quite efficient in integrating the emigrant population, especially at school. It is important to bear in mind that schools and the school environment are the main point of encounter between families of different cultures. There were significant difficulties incorporating foreign students in schools in the first decade of this century. The importance of integration in the process of normalizing relations between immigrant families and schools has been indisputable. However, one of the main difficulties with this integration has been the poorer performance and academic achievement of foreign students in the Spanish education system. Foreign students’ performance is significantly different. For example, they achieve significantly lower grades in the different standardized tests (Programme for International Student Assessment (PISA)), e.g., and higher rates of dropout, academic failure, and grade repetition. However, it is also true that these differences are significantly smaller for second-generation students born in Spain of immigrant parents. Faced with these facts, there have been numerous theoretical analyses and research projects that have tried to determine which variables affect this situation and which of them can be attributed to immigration, excluding any other socioeconomic factors. The results and the academic attainment of foreign- and immigrant-origin students in the Spanish education system are associated with some factors attributed to immigration. One of the most important is school segregation processes and their consequences for the educational and social integration of this group. Likewise, the financial crisis that has affected public policy and the Spanish welfare system, with the resulting budget cuts in education, has conditioned compensatory measures and attention to diversity.