Regulators increasingly use gender diversity disclosure regulations (GDDR) to promote female representation in corporate leadership positions through public pressure. Despite their far-reaching impact on corporate personnel decisions, evidence on efficacy of GDDR is limited. This study examines the disclosure practice and the development of gender diversity across management levels, the determinants of GDDR efficacy, and potentially unintended consequences of GDDR. The results show an overall increase in female leadership among companies affected by GDDR. Furthermore, the findings indicate that different determinants (e.g., public pressure) are associated with the efficacy of GDDR. Moreover, greater supervisory board gender diversity correlates with lower financial reporting quality in specific contexts under certain contextual factors. The empirical findings offer valuable implications for regulators, auditors, enforcement institutions as well as for users of gender diversity reports.