Purpose Since 2012, the Brazilian Stock Exchange has recommended that listed companies inform them if they have conducted voluntary disclosure. The purpose of this study is to describe the voluntary disclosure by companies listed in the B3 in Brazil and to analyze which characteristics of the board of directors influence this disclosure. Design/methodology/approach The study involves quantitative research using a sample of 285 companies and 575 reports from 2011 to 2014. A fixed-effects regression model with panel data was used for the analysis. Findings The results were statistically significant for gender and duality variables, which confirms the theory that the presence of women as members of the board positively influences voluntary disclosure and that chief executive officer and chairman of the board positions have a negative effect. The age and independence of the board variables did not present statistical significance. Research limitations/implications As a theoretical contribution, the authors aim to complement sustainability, finance and strategy research by using agency theory and measuring the variable of voluntary disclosure and the board, which is rarely studied in this context. Practical implications As social and empirical contributions, a better understanding of this theme in the context of emerging countries, which is the peculiarities of Brazil with little information transparency and well-known corruption scandals, is likely to aid investors. Increased access to company information can help investors better select their investment portfolios and assist in the choice of their board representatives in companies in which they have participation and voting rights. Originality/value The fact that Brazil is an emerging country, where the lack of transparency of information and corruption in these environments stand out the importance of studying the subject of voluntary disclosure in this context. All data were collected manually specifically for this research.