We explore the emerging logic of co-creation in a local public organization which corresponds to a new paradigm and a set of new practices in public management (Torfing et al., 2019). This research context is particularly relevant for institutional scholars as an emerging logic is significantly underdeveloped in terms of prescribed practices (Bertels and Lawrence, 2016) which reinforces the interest in managerial agency (Lynn and al., 2000). The emerging logic is marked by a lack of specification of institutional prescriptions which leads to a high level of ambiguity and uncertainty (Greenwood et al., 2011) challenging managerial practices. Bertels and Lawrence (2016) show that the context of emerging logic leads to specific organizational responses. Beyond the identification of organizational responses, we seek to understand how actors intentionally introduce an emergent and weakly articulated logic and how other actors in the same organization react. To do so, we mobilize the institutional work and materiality approach to understand such practices in a context of emerging logic. The institutional work approach helps to understand these efforts by focusing on the intentional practices of individuals and organizations to create, maintain or disrupt institutions (Lawrence and Suddaby, 2006). The material dimension3 of institutional work seems particularly effective in shaping emerging logics (Cloutier and Langley, 2013), but remains understudied in existing literature (Lawrence and Phillips, 2019). In this sense, we aim to better understand how actors use materiality as a “tool of institutional work” to induce change for co-creation practices in their institutions (Lawrence et al., 2013). Method: We used an exploratory and experimental research design based on a qualitative single-case study approach (Yin, 2015). The case study is a French municipality, and the experiment consisted of both developing a theoretical knowledge base to gain an understanding of the organization and the local context, as well as working with the municipality to design and implement co-creation experiments. The data collection combines a study of semi-structured interviews (one key political actor and five public managers within the municipality); participant and non-participant observation (an informal first encounter, three preparatory meetings, a day of training and two co-creation workshops) and secondary data. Analysis: The data has been analyzed thematically (Miles and Huberman, 2003). Our analysis included two steps: firstly, retracing the history of the case through the identification of the phases of institutional work. Secondly, identifying the logics at play, the forms of materiality and its roles in the institutional work practices. This allowed us to develop the data structure and identify patterns, linking the logics to elements of materiality and institutional work. Main findings: The results of the case study show that materiality is a medium of instantiation both for the emerging logic targeted by institutional work practices and for the logics present within the organization. Based on our findings, materiality is an enacting medium for the emerging logic, a revealing medium for dominant logics, and a confronting medium between the dominant and emerging logics. From a managerial perspective, our study emphasizes the strategic role of materiality in institutional change processes. While little attention is paid to material elements by both managers and neo-institutional scholars, our findings allow us to shed light on their roles.