The purpose of this paper is to analyse the nature of bureaucratization within public research bodies and its relationship to scientific performance, focusing on an Italian case-study. The main finding is that the bureaucratization of the research sector has two dimensions: public research labs have academic bureaucratization since researchers spend an increasing part of their time in administrative matters (i.e., preparing grant applications, managing grants/projects, and so on); whereas universities mainly have administrative bureaucratization generated by the increase over time of administrative staff in comparison with researchers and faculty. In addition, I show that research units with higher bureaucratization have lower scientific performance.