Based on comparative and qualitative researches, this paper shows that veto players influence policy making, but that in some fields (as in the judicial one), interest groups play a greater role. If we define veto players (VP) as the actors who have to agree for the legislative status quo to change (Tsebelis, 2002), we can identify four potential VP (especially in the executive) in Belgium, France and Italy: the parties which form the governmental coalition (depending on its degree of coherence and on parties’ discipline), some parties of the opposition (when the Constitution has to be modified), the Head of the State (who signs or promulgates a law) and the Constitutional Court. The importance of each VP depends on the political system’s characteristics, on constitutional features and on political practices. The past and present mobilizations of political and judicial actors (to support the reform or to interrupt it) give strength to these VP. Contrary to Tsebelis, there have been numerous judicial reforms in Italy despite a great number of VP. Therefore we should consider the role of other actors who can block a reform (for example, the electors through elections or abrogative referendum). Above all, the comparison shows that the ways the judicial professions are organized and mobilized have a stronger influence on the law making process than VP. The important differences of organization in the three countries mostly explain the unequal capacity of lawyers to be or not proposal forces in a reforming process, their degree of intern and extern legitimacy, their degree of unity as well as the particular balance of power between judicial professions. Therefore the analysis of law making implies to consider not only the institutional actors, but also the way interest groups intervene in the policy making (via the administration, the executives or the legislatives).