Recent literature seems to have opened up space for naturalistic theistic metaethics in a contemporary context, as proponents of divine command theories have tended to be restricted to either supernatural or theistic non-natural theories within existing taxonomies of normative theory. While perhaps encouraging for theists, would theism add anything substantive to theories of ethical naturalism? In this paper, I examine this question. I argue that theistic naturalism appears to incur certain objections as well as provide a plausible and explanatory constraint on content for theories of ethical naturalism. As a result, a corresponding challenge to non-theistic variants is raised. / Master of Arts / Realists, roughly summarized, are those metaethicists who believe that some moral propositions have truth values, that some (or at least one) of those propositions turn out to be true, and that if rational agents disagree on the truth value of a particular moral proposition, only one of them has the possibility of being correct. Broadly construed, moral realists tend to fall under one of two “tents”, preferring either naturalism (for which moral properties turn out to be wholly natural in constitution) or non-naturalism (which posits that at least some moral properties have, even if only partly, non-natural constituents as part of their make-up. Theists, who base their theories of morality on some facet of the nature or essence (or commands) of God, have tended to either be relegated in philosophical debate to a characterization of “supernaturalism” or to some seldom visited corner of the non-natural “tent” of moral realism. The former tends to limit theistic engagement in contemporary metaethical dialogue such that it can seem (at times) as if theists and non-theists are talking about two different subjects entirely. On the other hand, a non-naturalistic theory of theistic moral realism saddles the view with some fairly difficult metaphysical and epistemological baggage in the form of powerful objections levied against non-naturalistic theories in general. This paper explores another option for theism in light of very recent work by Gideon Rosen, namely his article examining the metaphysical implications of varieties of moral realism, particularly naturalistic ones. This article has already garnered a general characterization (within metaethical research, writ large) as being a “taxonomy” of naturalistic (and non-naturalistic, for that matter) theories. Specifically for my purposes here, Rosen suggests that divine command theory (and theistic metaethics in general) should be understood as being naturalistic in formulation. This would seem to be advantageous to theists, in that their metaethical theories might avoid either the bounded characterization of supernaturalism or the difficult challenges of non-naturalism. However, the theist, should she avail herself of naturalism in this regard, will need to tread carefully. Given that Rosen has couched his 'taxonomy' in terms of metaphysical grounding, I examine some resultant challenges for naturalistic theistic metaethics, concluding they can be overcome, as well as a related objection to non-theistic naturalism that arise as a result of the same grounding discussion coupled with the resources theists can leverage in a naturalistic context.