PurposeGrowing social concerns and ecological issues accelerate firms’ environmental, social and governance (ESG) engagement. Hence, this study aims to advance the existing literature by focusing on the interplay between institutional and firm governance mechanisms for greater ESG engagement. More specifically, the authors investigate whether public governance stimulates excessive ESG engagement and whether corporate governance moderates this relationship.Design/methodology/approachUsing a sample of 43,803 firm-year observations affiliated with 41 countries and 9 industries, the authors adopt a country, industry and year fixed-effects regression analysis.FindingsThe authors find that public governance strength via its six dimensions stimulates excessive ESG engagement. This implies that firms in countries with strong voice and accountability, political stability, government effectiveness, regulatory quality, rule of law and control of corruption are more motivated for ESG engagement. Furthermore, corporate governance negatively moderates the relationship between all public governance dimensions (except political stability) and excessive ESG engagement. This implies that public governance and corporate governance are substitutes for encouraging firms to commit to ESG. Further tests reveal that whereas these results in the baseline analyses are valid for developed countries, they are not valid in emerging markets.Research limitations/implicationsThe findings support the interplay between institutional and agency theories. In countries with strong (weak) institutional mechanisms, corporate governance becomes weak (strong) in inciting greater stakeholder engagement. This implies that the public governance mechanism alleviates agency costs, rendering internal mechanisms of corporate governance noncompulsory for ESG engagement.Practical implicationsThe findings suggest that emerging countries need to reinforce their institutions for greater accountability, regulatory quality and control of corruption, which will have a domino effect on firms in addressing stakeholder expectations. The results also advise emerging country firms to augment their internal monitoring mechanisms for greater stakeholder engagement, such as structuring boards and establishing corporate social responsibility mechanisms, committees and policies.Originality/valueThis study contributes to the recent literature investigating the role of corporate governance mechanisms in excessive ESG engagement. The study also explores whether public governance is associated with greater ESG involvement and provides a comprehensive analysis of the association between six indicators of public governance quality and excessive ESG practices in developed and emerging economies.