The notion of responsibility has a peculiar destiny in sociology. On the one hand, responsibility as such rarely emerges in the field. On the other hand, distinct concepts, which have been widely discussed in social theory, aptly capture various aspects related to responsibility itself. This article examines these intersections to define a frame of reference for a sociological reflection on responsibility. In doing so, it moves from four fundamental notions in social theory: (social) action, expectations, trust and uncertainty. Drawing on the social studies of science and technology, the article will apply this framework to explore how responsibility is enacted in science, technology and society encounters.