This study analyzes from an intersectional perspective how categorizations based on gender, class and ethnicity transform into inequalities in regard to school success. The study is based on data from an assessment in Sweden, where 6,788 students in ninth grade participated. Students’ overall grade scores are compared on the basis of gender, class and ethnicity. Class is operationalized with the help of the parents’ educational background, while ethnicity is rated based on the parents’ country of birth. The three background variables interact and form different patterns of inequality. Although parents’ educational level has considerable importance for school success, it interacts with gender and ethnicity in different ways. Boys as well as girls are disadvantaged by a low level of education in the home, while it is mainly girls who are disadvantaged by a foreign background.  Keywords:   intersection; education; school success.