A cassation court traditionally has two tasks: a unifying task and a corrective task. The unifying task consists of verifying the internal legality of a lower court’s decision (the correct application and interpretation of the law by the lower courts). The corrective task refers to verifying the external legality of the lower court’s decision. The cassation court must ensure that the decisions of the courts concerned are in conformity with the requirements of proper administration of justice. This article focuses on the following question: is it necessary that the Belgian Council of State, acting in the capacity of a cassation court, performs both traditional tasks (corrective and unifying)? This is by no means self-evident, given the specific judicial structure in which the Belgian Council of State operates.