Extant research on CSR communication has focused primarily on external communication, i.e. what firms communicate to their environment. At the same time, a large part of this literature exhibits a mechanistic understanding of communication that implies the possibility of a package-like transfer of information and meaning from sender to receiver. However, this notion of communication can be criticized for neglecting the constitutive role of communication for organizations. As an alternative, these authors propose a theoretical perspective known as “communication constitutes organizations” (CCO). The CCO view allows for grasping organizations as holistic and polyphonic communicative entities. Hence, what are the implications for CSR communication when we switch from a mechanistic to a constitutive notion of communication? Our application of the CCO view yields three main findings: (1) CSR communication represents only one of several communicative practices that collectively constitute the organization and that evolve in competition with one another; (2) CSR communication is not only a function of (large-scale) formal organizations, but as a communicative activity it can itself also form the constitutive basis for the emergence of rudimentary, local, and temporary forms of organizing; (3) According to the CCO view, organizations are constituted and stabilized by various non-human entities (e.g., texts or other artifacts) that “act” on their behalf. Thus, CSR communication would need to take also into account the agency and responsibility of these non-human entities, which in some cases lack concrete individual human creators who could be held accountable for. Taken together, our paper links the literature on CSR communication to broader debates in organizational communication studies. By applying the CCO view, we arrive at a new understanding of CSR communication that allows for comprehending the legitimacy and accountability of organizations as holistic communicative phenomena and helps to transcend a one-sided accentuation of the external side of CSR communication.