Purpose - This study aims to investigate the role of governance on knowledge acquisition and loss by new technology-based firms engaged in inter-firm collaborative new product development projects. Design/methodology/approach - This work draws on the relational exchange perspective, transaction cost theory and the resource-based view in order to develop hypotheses. Survey data collected from British new technology-based firms, operating in three industry sectors, was used to examine these hypotheses. Findings - Relational governance was found to have a positive relationship with the acquisition of knowledge-based resources. Increased comprehensiveness in the formal contractual governance structure was found to be associated with lower levels of harmful knowledge loss. Research limitations/implications - This study was conducted in one country. Future research should be done in different countries to determine the generalizability of the findings. Practical implications Managers engaging in collaborative new product development projects need to develop both relational as well as formal contractual governance mechanisms, so that positive collaboration outcomes can be maximized, while negative outcomes are minimized. Originality/value - A review of the literature indicates that the study of the governance of short-term, focused inter-firm relationships has been neglected. Additionally, while there has been extensive examination of knowledge acquisition there has been much less exploration of knowledge loss within these inter-firm relationships. This study contributes to the literature by responding to this need.