Purpose This article proposes a theoretical framework that synthesizes the main factors explaining the strategic contribution of communication department to open innovation (OI) processes. Because there is little or no research literature on communication and OI, the purpose is to fill this gap. A literature review and empirical qualitative research were conducted to weigh the significance of the framework in practice. Design/methodology/approach An interdisciplinary literature review was necessary to identify the main factors that explain the communication contribution to OI. The analysis of three multinational case studies has helped to enrich the proposed framework. Six semi-structured interviews were conducted with in-company communication managers and innovation managers in order to capture their perceptions. Findings Communication emerges as a strategic function with the potential to be embedded in the whole OI process. The main conclusion is that it may play an increasingly central role in enhancing relationships with external partners. Moreover, it enacts its strategic role while facilitating the enhancement of the organization's overall communication capability - that is, trust, transparency and a coherently articulated narrative. Research limitations/implications This article has not been designed as a comprehensive overview of the topic, nor it is designed to be statistically representative or generalizable. The study was conducted with the intention of exploring the theoretical and practical contributions of communication department to OI, as well as to raise awareness among scholars and practitioners on this new but neglected topic for research. Its qualitative approach serves to assess the value of the framework proposed, and the key issues highlighted here require further research. Practical implications The theoretical framework proposed may enable innovation managers to identify the factors in which the communication function and its practitioners may play a role for facilitating OI processes. Likewise, communication practitioners may find it useful to foster their organizational role and capabilities within these processes. Originality/value This article underlines the significant contribution that the communication function may play in OI processes. Research on this topic has been neglected thus far, despite its significance for the competitiveness of companies and the economy as a whole.