The article analyses judgment No 210.000 of 21 December 2010 of the Belgian Council of State, which deals with the question of the lawfulness of the prohibition on the wearing of a religious sign by a teacher of a subsidised official school. This decision is first set in the socio-historical context of the evolution of relations between state and religion in Belgium. The reasoning developed by the Council of State with regard to non-discrimination, on the one hand, and religious freedom, on the other, is then critically examined in the light of the relevant European standards.