The Mercosur Parliament (Parlasur), created in December 2006, is often considered an important institutional achievement. Although Parliament’s functions and competences are not large, it should be formed by directly elected representatives. Its Constitutive Protocol affirms the necessity of reinforcing and deepening the integration process. According to the document, it is essential to have an efficient and balanced institutional structure, which would contribute to the production of effective norms in an atmosphere of security and stability. Official speeches from Executive and Legislative authorities of member states tend to go in the same direction, asserting the democratic role of the assembly. Consequently, expectations about the performance of Parlasur are high among non-state actors involved with the integration process: some seem to believe that this new institution could conduct more vigorously the discussions to the political and social spheres, which would allow Mercosur to transcend the commercial aspects and strengthen the integration framework. If we accept the idea that the more institutionalized the legislature is, the more it will influence the political system, the institutionalization level of Parlasur can indicate at what extend these prospects are valid. This paper has therefore a double objective. First, it aims at analyzing the limited institutionalization of the assembly in terms of autonomy, complexity, universalization and socialization. Second, it searches to explain the gap between discourses about Parlasur and its current actions. The qualitative research intends to confront public declarations with minutes and verbatim reports of plenary sessions as well as with interviews conducted with members of the Parliament and national civil servants. The conclusions will hopefully help to understand the place of Parlasur within the rhetorical integration of Mercosur and its concrete possibilities of influencing regionalism and democracy in Latin America.< Leer menos