Nowadays the governments of industrialised countries, in the presence of reduced public resources, have to assign clear objectives to public research laboratories to increase the competitiveness of firms. The purpose of this article is to analyse the public research bodies of the National Research Council of Italy in order to pinpoint the main typologies operating in the national system of innovation (NSI). This research shows four main types of research institutes as drivers of NSI. The results can supply useful information to policy makers on the behaviour of these structures and on their strengths and weaknesses.