Constructivism appears to have taken a place in the literature on international relations (IR) theory in direct opposition to realism. Constructivists who claim their methodology is incompatible with realism focus on the association between realism and both materialism and rationalism. Realists who claim their paradigm is incompatible with constructivism focus for the most part on a perceived tendency for constructivists to be idealists or utopians. Neither argument, however, holds up. This essay examines constructivist epistemology and classical realist theory, contending that they are, in fact, compatible; not that constructivism is necessarily realist, but that constructivist research is as compatible with a realist worldview as with any other. Having a realist constructivism could prove useful in IR theory beyond clarifying methodological debates, including helping to specify the relationship between the study of power in international politics and the study of international relations as a social construction.