Introduction: One of the objectives of the third phase of the National Nutrition and Health Program was to reduce social inequalities in physical activity (PA) levels. In this context, an experimental program to promote PA was developed in a neighborhood of the city of Saint-Denis. The objective of this study was to evaluate its impact. Materials and Methods: Two assessments of PA levels were conducted—one before (2013) and one after (2015) the program’s implementation. Participants were selected by random drawing using a stratified cluster sampling method. The primary outcome measure was the change in the percentage of participants engaging in at least moderate PA, as measured by the RPAQ questionnaire. Results: The proportion of people engaging in at least moderate PA increased from 48.1% in 2013 to 63.5% in 2015 (p=0.001). Conclusion: This study demonstrated a significant increase in PA in a neighborhood of Saint-Denis where the program was implemented. External interventions occurring in parallel with the project may have contributed to this result.