In this article we make an attempt to examine the relationship between knowledge society and perception of uncertainty both at conceptual as well as empirical level. The discussion is placed in the context of late modernity. The more optimistic views see in the knowledge society the possibility for progress, higher quality and safety of life. Other reflections draw attention also to different crisis-related tendencies and stress the possibility of generating uncertainty as a possible side effect of a developed knowledge society. We observe two trends that appear with the development of a knowledge society: the perception of existing certainty increases, but at the same time we can also see the increase of a desire for and openness to greater uncertainty in a society. Using qualitative comparative analysis we find that developed knowledge society is a sufficient condition for greater openness to uncertainty.