The first goal of this article is to assess, for each country belonging to the Organisation for Economic Co-operation and Development (OECD), the influence of pupils' sociocultural background on educational aspirations. The second goal is to explore whether, after controlling for educational achievement, the residual influence of sociocultural background is still significant. In addition, the author estimates whether the sociocultural and academic characteristics of school composition have an additional impact on educational aspirations in this group of countries. Finally, he shows that the structural characteristics of school systems moderate the influence of individual characteristics and school composition on educational aspirations. (Contains 7 notes and 6 tables.)