Résumé : This research evaluates the effectiveness of FOI policy implementation in Belgian municipalities, using citizen science methodologies for data collection and interpretation. The results reveal significant variations in compliance across regions, with larger municipalities demonstrating greater responsiveness to FOI requests from citizens. A critical finding is the hesitant response of administrations to inquiries from citizens known for their transparency expertise, indicative of a widespread defensive administrative stance towards FOI requests within Europe. The study proposes policy reforms, increased support for smaller municipalities, and efforts to modify administrative culture towards a more transparent handling of citizens’ FOI inquiries. These recommendations are designed to enhance the implementation of FOI policies, promoting increased transparency and accountability within public administration, and encouraging an environment of openness in line with democratic governance principles.