This article introduces Luhmann’s theory of social systems as a prominent example of communication as constitutive of organization (CCO) thinking and argues that Luhmann’s perspective contributes to current conceptual debates on how communication constitutes organization. The theory of social systemshighlights that organizations are fundamentally grounded in paradox becausethey are built on communicative events that are contingent by nature. Consequently,organizations are driven by the continuous need to deparadoxify their inherent contingency. In that respect, Luhmann’s approach fruitfully combines a processual, communicative conceptualization of organizationwith the notion of boundary and self-referentiality. Notwithstanding themerits of Luhmann’s approach, its accessibility tends to be limited due tothe hermetic terminology that it employs and the fact that it neglects the role of material agency in the communicative construction of organizations.