The goal of the current study was to explore the role and importance of the facilitator in teacher design teams. The study took place in the context of a pre-service teacher education institution in Belgium, where teacher design teams were set up to facilitate the professional development of teacher educators. The findings from focus-group discussions with team members and semi-structured interviews with facilitators confirm that the perceived importance of a facilitator depends on several factors, such as team characteristics and the design phase. Moreover, we found that a facilitator can fulfil three roles in a dynamic way: (a) providing logistic support, (b) scaffolding the design process, and (c) monitoring the design process. The discussion centres on how these results can be used to support facilitators for successful Teacher Design Teams.