The Portuguese Parliament (Assembleia da República) until today is characterized by a relative high level of turnover of MPs. This permanent loss of expertise provides challenges for the parliamentary parties. In this paper, we analyze the resulting division of labour within the parliamentary parties and how it has helped to create and perpetuate a system where a small but powerful party elite controls much of the key positions and exercises control over many areas of parliamentary activity. This was a direct response to the challenges posed by the democratization process and the need for stabilizing the institution. While this pattern persists, we can show that it has got weaker over time, strengthening the professionalization of the Portuguese parliament.