Résumé : In most West European Democracies, parties have undertaken several internal changes. A common trend in these evolutions is the democratization of intra-party life through the empowerment of members in several respects (candidates and leaders selection, etc.). For pillar parties, these modifications have a peculiar signification as it could modify some of their core characteristics (oligarchy, overlapping membership and leadership, etc.). In that context, this article examines both the internal reforms in Belgian pillar parties and their impact. The three traditional Belgian party families linked to a pillar (Christian Democrats, Socialists and Liberals) have opened their membership procedures and democratized leaders and candidates selection. Though, the changes are more formal than effective. The internal reforms of Belgian pillar parties did not affect the core elements of this type of parties, which are elite control via oligarchy, and societal segmentation via overlapping membership and leadership.