Chinese high-tech firms urgently depend on interfirm coordination to improve new product development (NPD) innovation. While there is an increasing research interest in investigating the performance effect of supply chain coordination in Western countries, little attention has been paid to whether and how NPD coordination influences innovation performance in China. By incorporating the knowledge-based view of the firm and a dyadic perspective of knowledge transfer, this study explores the relationship between NPD coordination and innovation success, as well as the mediating roles of knowledge sharing and knowledge hiding. We test the hypotheses using data collected from 131 Chinese interfirm NPD projects. The results reveal that NPD coordination is positively associated with innovation performance. As expected, as NPD coordination increases, interfirm projects can benefit from a higher level of knowledge sharing and a lower level of knowledge hiding among stakeholders. Moreover, the positive performance effect of NPD coordination is partially mediated by knowledge sharing and knowledge hiding, highlighting the need to manage counterproductive knowledge transfer in collaborative supply chain innovation. Finally, theoretical implications, managerial suggestions, and future research directions are discussed.