The article deals with the issue of procedural flexibility from the perspective of the theory of the legal process as a guarantee. Starting from a dogmatic method, it seeks to differentiate the flexibility of the procedure and the adaptability of jurisdictional protection. It demonstrates that the criticisms made to the common procedure and procedural rigidity in Brazil follow premises of Italian doctrine. It clarifies that the criticism of procedural flexibility by the judge does not mean a disregard for material right. Finally, it looks at issues of comparative law. The bibliographic review method is used, in the construction of premises, and the deductive method in the formulation of the theses defended by the study.