To systematically create and share product development knowledge creates challenges for engineering companies. This paper presents an extensive study regarding the process of identifying such challenges in managing product development knowledge from the perspective of designers and engineers. This research is part of the LeanPPD, a project funded by the EU-PF7 (www.leanppd.eu), to address the need of European manufacturing companies for a new model, which extends beyond lean manufacturing and incorporates lean thinking into the product design and development process. A rigorous research methodology has been employed, which included the use of questionnaires and focused interviews with key informants from industry, involving forty-two product development engineers from nine different companies. The most significant concerns raised during the study concerned knowledge life cycle activities, product development environment and management. Thirty-eight challenges were identified, classified and discussed in order to provide the knowledge management community with practical evidence, and also to inform future research directions in managing product development knowledge. (C) 2014 Elsevier B.V. All rights reserved.