Although “dialogue of civilizations” is not a wholly new concept, its popularity was due to its being reintroduced by the Iranian President in the late 1990’s. As a notion in international relations, it has significant theoretical implications at different levels including ontological, epistemological, sociological, and normative. It is, however, theoretically underdeveloped. Among the theories of international relations, the so-called critical international theory might be seen as one of the best theoretical contexts for understanding and conceptualizing the theoretical contribution of dialogue of civilizations. This paper attempts to clarify this contribution. Critical theory is best known for its emphasis on dialogue and discourse and on the way that dialogue can shape the foundation for truth, objectivity, and consensus. At the international level, these may have more specific implications both in meta-theoretical and theoretical aspects. This paper will show how ontologically this idea can alter the state-centric conception of international relations. Epistemologically, it may function as a basis for non Euro-centric conceptions of international relations. Sociologically, it is a way towards the formation of moral community. And finally it is normatively oriented towards a less-exclusionary, fairer world politics. It will be argued that in all these four aspects it is more or less consistent with meta-theoretical, theoretical, and moral commitments of critical international theory.