Objective: the objective of this article is to verify if there is a critical mass of women to be reached in the board of directors to impact the extent of disclosure of information of a social nature and if the functional training and experience of the director in the sector of activity of the companies moderates this relationship.   Theoretical framework: the research is based on studies on how the characteristics of the members of the board of directors affect the decision-making process about the disclosure of information of a social nature, using the literature on corporate social responsibility and the theory of the mass criticism.   Method: the research is quantitative, descriptive, carried out by linear regressions with fixed effects panel data. The tests were applied to a sample of 104 publicly traded companies that voluntarily disclosed sustainability reports over a five-year period (2016 to 2020).   Results and conclusion: The main findings reveal that the presence of women on the board of directors positively affects the extent of disclosure of information of a social nature. The critical mass of 4 women or more positively impacts the extent of disclosure of social information. And, when there is a critical mass of 4 women, the extent of this type of disclosure increases by 9.95%. The board member's functional training and experience in the company's sector of activity were not significant to moderate the relationship between the critical mass of women on the board and the extent of disclosure of information of a social nature.   Research implications: the study has implications for academia, companies and regulatory bodies, as it implies the structure, composition and functioning of boards of directors, and the advantageous knowledge of the number of women needed on boards to make a difference in the improvement of policies for dissemination of social responsibility information.   Originality/value: the research innovates by verifying the percentage of variation in the rate of disclosure of information of a social nature when there are one, two, three, four and five women on the councils; and when it includes moderation variables to verify if the individual characteristics of the council members moderate the relationship studied.