This article aims to discuss the contemporary activities and roles that scientific associations play in science and society. It is based on a comprehensive study of scientific associations in Portugal, relying on a multi-method, quantitative and qualitative approach. After a brief review of the literature on associations in the social studies of science, we provide an outline of the expanding field of scientific associations in Portugal. We then proceed to present and discuss the five main roles of associations identified through (...) the research: communication among peers, promotion of research, science dissemination, representation of professional interests and policy advice. We conclude that the external roles of associations have become more important than the internal ones. Whereas the internationalisation of science has moved the communication, collaboration and competition between researchers into the transnational sphere, the links that associations forge between science and other social spheres are still deeply rooted in national settings and much dependant on specific configurations and practices by government, business and other social actors. (shrink)