As the reform of French institutions is currently once again open to question, both in terms of legal doctrine and in political discourse, this article considers the issue of the nature of the French political regime established by the Constitution of 1958. Although the regime has been subject to many changes, it is worthwhile to recall the true nature, in a legal sense, of the Fifth Republic as a parliamentary rather than a presidential system. In order to make this case, the relationship between the executive and the legislative power is analysed. To resolve any doubts, it is helpful to note that the legal criteria of the parliamentary system, such the political responsibility of the government to the National Assembly, are fully verified in the Constitution and therefore affirm the parliamentary nature of the Fifth French Republic. Of course, such an analysis is not enough on its own. Indeed, the Fifth Republic, which has been as subject to political uncertainty as its predecessors, is not static and therefore supports several political practices that should be identified and analysed in order to answer the question of whether the regime could evolve. In our view, such a question must be answered in the negative. The Fifth Republic is a parliamentary system, whose nature does not change but is capable, through a flexible use of words and interpretations, of permitting several political practices ranging between the presidentialism and parliamentarism.