Assuming that free school choice is one of the parameters contributing to segregation in the Belgian educational system, the government implemented decrees to alter school enrolment policies in order to regulate school choice. In this study, two statistical approaches (a 'Lorenz' index and a multilevel one) have been used to measure the evolution of segregation from 2006 to 2015 exploiting two databases (administrative student count and the Programme for International Student Assessment). The results do not provide any support to the claim that there has been a reduction in school segregation, and they stress that the decrees are inefficient concerning this objective.