In recent sustainability assessments, transdisciplinary approaches have been used to bridge contested normative views among many societal actors, policymakers and researchers. Transdisciplinary research is mainly based on three premises: (1) various perspectives need to be incorporated and discussed to empower actors, (2) the collaboration and co-creation of knowledge between academic and societal actors allows to better grasp the complexity of a real-world problem, and (3) a mutual learning process arises which could increase the legitimacy of decisions and their implementation in practice. Despite many examples of transdisciplinary projects, few assessments have been done that question whether such a project fulﬁls the premises of transdisciplinary research. Therefore, we report on a reﬂexive assessment of an initiative set up to foster the transformation of the Flemish agri-food system towards sustainability. The case study involved both scientiﬁc and societal actors with diﬀerent views, making it possible to implement a transdisciplinary process, evaluate the expectations and give suggestions for future processes. Evaluation criteria are linked to context, process and outcomes. Analysis of the qualitative and quantitative data indicates that the initiative did empower the transformation towards sustainability. Furthermore, results show that, in this case, a transdisciplinary approach can fulﬁl its premises. However, some critical factors are identiﬁed, such as the importance of the context speciﬁcity and a ﬂexible, adaptive and iterative process.