Multinational corporations (MNCs) can innovate with external organizations by forming innovation networks. Previous studies focus more on the motives or outcomes of innovation networks but pay less attention to configurations of innovation networks such as the members involved. Taking the perspective of an MNC, in this paper we explore the factors affecting the configuration of product innovation project-based networks. This study adopts a multiple cases study approach and both radical and incremental product innovation project-based networks are examined. We provide a typology to classify project-based networks based on the scale of internal members joining a project and the scale of external members joining a project. We find that diversity of products, importance of projects, newness of projects and complexity of technology affect the configuration of product innovation project-based networks.