Companies increasingly turn towards users for inspiration to develop innovative products and services. Living labs (LLs) represent a new way for companies to engage in co-creation and to better understand user needs. LLs interact with a wide set of stakeholders, such as customers, companies and universities. Therefore, coordinating co-creation is particularly complex, as it requires the inclusion of more activities and actors than those of traditional closed innovation models. It is thus crucial to identify how co-creation can be facilitated in LLs. In spite of a growing body of literature, an understanding of those factors facilitating cocreation in LLs is still lacking. To fill this gap, the perspectives of three key stakeholders, the LL facilitators, companies and co-creators, are considered. This study employs a qualitative explorative approach in the form of a holistic single-case study. A bottom-up theory building approach based on rich qualitative data, collected through interviews, focus groups, observations, questionnaires, and documentary information, is chosen, and grounded theory identified as a suitable approach. Contributions from this thesis are captured in ‘The Five Ps for Co-creation Facilitation in Living Labs’ framework which presents the conditions to allow for systematic and tailored facilitation services. The five Ps - Purpose, Principles, People, Place, and Prize – build the cornerstones of this framework. This thesis suggests that it is important to understand the purpose behind a company’s co-creation project to tailor the facilitation service to its needs. Indeed, seven distinct categories of project objectives are reported. Furthermore, this study identifies seven principles influencing the interaction of People and Place of the LL. Finally, eight categories of project outcomes are recognised, referred to as Prize. This study contributes to the research on co-creation in LLs and provides guidelines for practitioners that would like to engage in such open innovation activities.