The issue of infinity appeared in cosmology in the form of a question on spatial and time finiteness or infinity of the universe. Recently, more and more talking is going on about “other universes” (different ones from “our”), the number of which may be infinite. Speculations on this topic emerged in effect of the discussions on the issue of the anthropic principle, and the so-called inflation scenario. In truth, this kind of speculations are hardly recognized as scientific theories, however, they may be included in a sort of “scientific fringe” fulfilling a beneficial heuristic function.All of the speculations regarding numerous universes boil down to the juggling of probabilities, i.e. to the applying of the theory of probability to the universes’ set. However, without probabilistic measure being introduced onto this “set” (as it is not known whether it is a set in a technical sense of this term)—and there is no knowledge at all as to how to do this—such considerations may not go beyond a vague intuition.The producing of other universes usually results from an assumption that the disturbing of original circumstances, of values of physical constants, or of other parameters characterizing the universe is possible. On the other hand, the idea of the final theory seems to assume that the mathematical structure of this theory should be rigid, i.e. that the disturbing of its parameters leads on to the very same structure. This would have eliminated the possibility of the existence of other universes.The idea of infinite number of universes sometimes has an anti-theological undertone: there is no need for assuming purposeful acting of the Creator, since all possibilities are fulfilled. The reaction of a theologian may be as follows: Just the same, God may create just a single universe, as much as an infinite number of universes. What’s more, one may risk saying that God is not interested in nothing that may be short of infinity.