This study examines how China’s 2012 anti-corruption campaign affected corporate social responsibility (CSR) disclosure among politically connected firms from the perspective of CSR dishonesty. We find that politically connected firms significantly reduce their CSR disclosure relative to unconnected firms following the campaign. The evidence suggests that anti-corruption weakens political patronage that previously enabled symbolic CSR practices and increases the exposure risk associated with dishonest disclosure. Consequently, connected firms adopt a more cautious disclosure strategy, particularly when external scrutiny is stronger. Our findings highlight how political ties shape firms’ non-financial reporting incentives and demonstrate that anti-corruption can curb impression management behaviour.