The purpose of this paper is to defend the so-called Ostrich Nominalism against the influential criticism that has been put forward by David M. Armstrong. First, I reconstruct Armstrong’s “One over Many” argument for universals (§§ 1-2), reviewing his main reasons for rejecting the foremost kinds of nominalism (§ 3). I then argue that Ostrich Nominalism has been underrated by Armstrong (§ 4) and that, consequently, his strategy for dealing with it results in misleading and elusive conclusions. I conclude that Ostrich Nominalism represents an arduous challenge to Armstrong’s Realism in that it compels him either to give up his sparse Realism, or to acknowledge that all the solutions to the problem of universals are utterly meaningless (§§ 5-6).