Education is a complex system with implications for educational policy and management. Education systems that are more comprehensive generate more equal outcomes, fostering access to opportunities for all children. On the other hand, systems with early selection and tracking are more stratified and register higher inequalities in educational outcomes. Educational inequalities imply unequal access to education and, subsequently, career opportunities. The present study employs classification techniques, such as decision trees, in order to highlight lines of stratification and inequality in the upper secondary education system in Romania, focusing on the selection of students in general or vocational programs. Our results show that the education of parents and area of residence are factors that influence the stratification of students in the Romanian secondary education system, and the selection process contributes to the reproduction of social inequalities. The conclusions of this study are consistent with the cultural capital theory in education. Policy and strategic management implications are discussed in light of our results.