Catholic social teaching is the Church’s “best-kept secret,” as the saying goes, but is it becoming literally true? This paper tests the proposition that the US bishops are developing a pattern of obscuring or, in effect, hiding particular social teachings of the popes. The instances examined include the ideological error of single-issue advocacy; the meaning of the right to form labor unions; and the intrinsic value of nonhuman species and ecosystems. It would be true irony if the “best-kept secret” were that the bishops were actually keeping a secret. The paper contends that this expression, now more than a metaphor, has acquired a double meaning to which one ought to attend, for papal social teaching should be openly embraced and handed on to the faithful.