Introduction: This article assesses the impact of social accountability, implemented through municipal public policy councils in the fields of health, education, and social assistance, on corruption. Materials and methods: The study adopts a quasi-experimental research design within a robust causal inference framework. A set of estimation techniques, such as regression, propensity score matching, and instrumental variables, is employed to establish a counterfactual for analyzing a random sample of 1,223 municipalities independently audited between 2006 and 2015 as part of the Municipal Oversight Program of the Brazilian Office of the Comptroller General. Findings: Statistically significant effects of social accountability, carried out through public policy councils, on corruption in Brazilian municipalities are observed. When these councils are operational and active, and effectively exercising their legally mandated roles, a statistically significant reduction in the occurrence of corruption cases is evident. Discussion: Findings align with the international literature, emphasizing the positive impact of social accountability in the fight against corruption. The proposed theoretical model elucidates how operational public policy councils, through monitoring, regulation, consultation, and decision-making on local programs, play a key role in promoting social accountability while overcoming the ‘social fence dilemma,' bolstering the necessary collective action for public integrity. However, corruption is a complex problem that demands a multifaceted approach, and further research is required to delve into strategies for optimizing the performance of public policy councils. The study contributes to a more evidence-based design of democratic anticorruption policies.