This article relies on the literature on technology adoption and empirical studies on social media adoption in the public sector to analyze the case of Belgian municipalities. Our objective is threefold as we aim to a) provide a new approach to assess the adoption of social media platforms by governments, b) describe the current situation in Belgium through the concept of ‘active adoption’ and c) determine the main factors that relate to the uptake of Facebook in Belgian municipalities over 10,000 inhabitants. To achieve these objectives, we used a software to retrieve quantitative data regarding Facebook adoption and institutionalization. Our results reveal that municipality size, median age and longevity on the platform are positively associated with the adoption of Facebook. In contrast, median income is, surprisingly, negatively associated with several dimensions of active adoption. These findings contribute to the literature on the factors related to social media use. In addition, the new ways to uncovering social media adoption and institutionalization patterns provide a solid conceptual approach for future research. For practitioners, our study provides municipalities with a better assessment framework and offers them a new model to evaluate social media adoption, underlining the fundamental difference between registration and “active adoption”. ; info:eu-repo/semantics/published