The sociology of education often emphasizes the father’s occupation as a determinant of inequality of educational achievement. However, other factors such as household income and parental educational attainment are important as well. Educational attainment is typically interpreted as the “cultural” dimension of parental capital. But there are other criteria for evaluating that dimension, such as cultural participation, familiarity with the education system, and skills. Our article offers, for the first time, a statistical insight into the skill factor through an analysis of the 2004 Information and Daily Life Survey (Information et Vie Quotidienne: IVQ). Parents with the lowest reading and mathematical skills have children who repeat classes more often than others. The correlation persists even after testing for the other available characteristics such as education, income, and occupation. Its form differs according to the gender of the parent examined. It is better to have a father who is good in mathematics and a mother who is good in French than the opposite. This may indicate a division of labour in help with homework: fathers help with mathematics, and mothers help with French. However, skills are not the only characteristics linked to backwardness at school. Parental educational attainment, household income, and cultural participation also generate major differentials.