The article is devoted to explaining differentials in student achievement related to social origins. In particular, Italian data drawn from the Pro-gramme for International Student Assessment (Pisa) are used to submit cultural capital theory to empirical scrutiny. The analyses indicate that cultural resources provide a relevant, but far from exhaustive, account of inequalities in schooling. It is also suggested that Pierre Bour¬¬dieu overes-timated the cultural homogeneity of social classes in contemporary socie-ties, which may explain the weakness of his theory. Finally, it is sug-gested that, in order to elaborate a more satisfactory explanation, more attention must be paid to occupational aspirations, economic resources and the dynamic dimension of educational careers.