PurposeThe deeper understanding of the disclosure of external and internal dynamics of family firms necessarily places the issue of sustainability as one of the most pressing needs from both a research and managerial perspective. Therefore, this perspective article contributes to the debate of sustainability performance disclosure in family firms, proposing a research agenda.Design/methodology/approachThis study has organized the discussion around those elements that most significantly impact the propensity to disclose, with a specific focus on the interconnections and interrelations within them. The proposed research agenda is developed around three key elements: “how” firms disclose, “the reason why” they do it and “what” disclose of their performance(s).FindingsTo better understand “how” family firms should disclose their performance, it is suggested to engage in proactive stakeholder engagement to preserve long-term socioemotional wealth. “The reason why” for disclosure is still associated with the legitimization of family firms from an economic, social and environmental point of view. Finally, the “what” depends on several factors, such as the regulatory framework and the market involved.Practical implicationsThis paper contains suggestions for family firm managers, consultants and policymakers that are approaching corporate social responsibility (CSR) and non-financial reporting or sustainability disclosure overall, providing an overview of relevant factors influencing this transition process.Originality/valueThis paper suggests a logical framework to combine these three elements of the debate as strictly interrelated to foster the sustainability performance disclosure of family firms.