The VoisinMalin association, which works in priority neighborhoods, and the National Institute for Demographic Studies (INED) have joined forces to conduct action research on occupational health. This participatory initiative involved some twenty “Voisins malins”—part-time employees of the association—who live in three neighborhoods in the Île-de-France region. From designing a questionnaire to conducting a door-to-door information campaign, these individuals contributed their perspective on real-world conditions to the scientific data collection. This pioneering project foreshadows future collaborations between researchers and community-based actors.