The capacity of organizations to share knowledge is seen as a source of competitive advantage in many industries. Knowledge sourcing and knowledge reuse have been indicated as important enablers of organizational efficiency and innovation performance. Although firms may own valuable knowledge, the presence of barriers to knowledge sourcing and reuse may hinder the exploitation of such knowledge. The present study explores the barriers to knowledge sourcing and reuse and their implications within the virtual product prototyping stage of new products development. The study is based on 24 interviews with R&D employees of a large supplier of R&D in the automotive sector. Results demonstrate that the low operational quality of a repository may hinder knowledge sourcing; therefore, people prefer to source knowledge from other colleagues. Additionally, the inefficiencies in knowledge sourcing from a repository, the low quality of the codified knowledge, and its complexity affect the reuse of existing knowledge. This study reveals that knowledge sourcing and knowledge reuse are important knowledge management processes in the product prototyping and that inefficiencies in these two processes may negatively affect the time performance in the new product prototyping process. Copyright © 2015 John Wiley & Sons, Ltd.