Managing the communication between the participants involved in inter–organizational product development is complex. The traditional models of new product development are not sufficient to gain insight in effective management practices in this respect. Our study explored the inter–organizational communication in a research and development project. Our results confirm Gersick’s model that looks upon new product development as being punctuated by periods of rapid change. In these periods, including the start–up, explorative prototype stage, and completion of the project, inter–organizational communication is essential about design objectives and project planning, contextual factors and the required resources, skills and knowledge.