Disclosure has a key role regarding the functioning of the capital markets, being essential to support an adequate evaluation of the investment opportunities by the economic agents, by reducing information asymmetry. Literature shows that several factors affect disclosure level decisions and, considering that in Brazil the main agency conflict occurs between controlling and minority shareholders, it is reasonable to consider that corporate governance characteristics may represent an explaining factor of disclosure decisions. This paper intended to detect the relation between corporate governance and disclosure using Ordinary Least Square regression method, as well as Tobit model, for the year 2002. Disclosure was used as the dependent variable (a disclosure index was specially elaborated for this research) and five corporate governance variables were used, two related to ownership structure, which are control rights (BLOC) and difference between control and cash flow rights held by controlling shareholders; as well as three variables related to the board of directors, which are size (CONS), independence (INDEP) as well as presence of the chairman of the board being the president of the company (PRES). Relation between disclosure and corporate governance in principle is uncertain and it is assumed that it can be complementary or substitute, in order to identify whether in a environment of weak monitoring of managers and controlling shareholders companies would be motivated to be more transparent (to compensate for an inadequate corporate governance level), or the opposite (companies would be less transparent because they would not have incentives to disclose information). Results for DIF variable supported the substitute effect, while results for INDEP variable in the Tobit models confirmed the complementary effect, showing that the level of board independence is relevant for companies which are not transparent start to be. The other corporate governance variables in general were not statistically significant. Additionally, a sample of companies who raised resources in the market was selected and, in general, results were similar. Regarding control variables, it was detected that companies with controlling shareholders being domestic and private, bigger companies, with higher financial leverage, better valuation and better performance tend to be more transparent. This paper aimed to contribute for the discussion on the subject given the lack of research in the Brazilian context. The search for an ideal disclosure level as well as good corporate governance standards (protecting investors against expropriation) seek to contribute for the economical and institutional development of the country.