Purpose: Extant literature has devoted more attention to customer value co-creation and knowledge sharing, not only in business-to-customer (B2C) markets, but also in business-to-business (B2B) markets. This study explores and examines the antecedents and consequences of customer knowledge sharing in the context of B2B markets by applying the motivation-opportunity-ability (MOA) framework. Methodology/Approach: This empirical study involves two structured surveys of project managers from both suppliers (n = 213) and customers (n = 312), which were conducted in the context of the Chinese telecommunication service industry. The conceptual model of this study was subsequently tested by developing Partial Least Squares (PLS) based structural equation models. Findings: It was found that customer knowledge sharing is facilitated by four MOA factors: customer orientation, customer perceived benefits, customer socialization, and customer technological capability. It was determined that knowledge sharing has a direct and significant effect on project performance. Furthermore, the study revealed that such relationships vary across suppliers and customers. Research Implications: This study extends the existing research stream of interfirm knowledge sharing by examining the antecedents and consequences of customer knowledge sharing from dual perspectives of customers and suppliers, and sheds light on the benefits of customer knowledge sharing. The dyadic perspective embodied in this design facilitates our understanding and management of knowledge sharing between organizations. Originality/Value/Contribution: This article provides an important contribution to the existing literature of customer knowledge sharing by revealing how to effectively facilitate interorganizational knowledge sharing, particularly knowledge from customers to suppliers, and discovers conditions under which customers are more likely to exchange information, and share knowledge with their suppliers from the dyadic perspective. © 2013 Copyright Taylor and Francis Group, LLC.