Communication between the CIO and the CEO is important to achieve a shared understanding of the current and future role of IT in an organization. Such a shared CIO/CEO understanding has been shown to positively affect organizational IT success. Despite the importance of CIO/CEO communication, only a few studies have examined how CIOs and CEOs can achieve effectiveness in their interactions. To advance knowledge on CIO/CEO communication, we integrated existing research findings into a CIO/CEO communication model, and derived corresponding propositions. In essence, the model posits that CIO hierarchical position influences CIO/CEO communication effectivity, which, in turn, influences the shared CIO/CEO understanding on the current and future role of IT in the organization. A shared CIO/CEO understanding on the current role of IT influences both CEO support for strategic IT initiatives and CIO/CEO perception of IT contribution to business performance, while a shared CIO/CEO understanding on the future role of IT influences the CEO support for strategic IT initiatives.