By examining the way in which Luhmann addresses the issue of technological risk, the author of this article highlights a conceptual tension: on the one hand, Luhmann constructs a theory of the society of communications, based on the principle of its decomplexification through an on-going process of functional differentiation; on the other, he develops a theory of technological risk in which he considers that the social system lacks communicational solutions for treating this theme. This difficulty paves the way for a conceptualization of the risk issue which, owing to a comeback of public opinion, reconciles the (Luhmanian) distinction between risk and danger, with the (Habermassian) one between the system and the life-world.