This study investigates the role of knowledge-sharing between supply chain actors in facilitating their adoption of Industry 4.0 technologies, identifying factors that hinder or promote such knowledge-sharing. Drawing on an in-depth single case study, including 19 interviews with a manufacturing firm in the German automotive industry and five of the suppliers and customers in the focal firm’s supply chain, the study identifies the following knowledge-sharing approaches that facilitate the adoption of Industry 4.0: 1) knowledge-sharing through principles; 2) upstream flow of knowledge; 3) strategic positioning; and 4) application-relatedness. These approaches are shown to be influenced both by company-related factors and relational factors. Applying a knowledge-based view of the firm, this study addresses a gap in current research by investigating the role of knowledge-sharing in adopting Industry 4.0 from the perspectives not only of a single focal firm but also of upstream and downstream suppliers and customers in the supply chain. In presenting approaches to knowledge-sharing that promote the implementation of Industry 4.0 based on a firm's existing resources, this study is also of direct relevance to practitioners.