This study estimated the quality of governance practiced by a significant sample of Brazilian publicly traded companies between 2002 and 2006, and related it to risk and performance. An index composed of twenty questions, with all answers in binary form, was constructed to measure the quality of governance. Several indicators were used for risk such as the local beta, the beta obtained with the use of the S & P 500 index, share price volatility, idiosyncratic risk and the implicit cost of capital. Measures of performance were the following variables: return on assets), return on equity, the margin of ebit-to- sales, and the ratio of market value-to-sales). The results obtained through the application of the method of simple and multiple linear regressions, in increasing level of complexity, were confirmed, with robustness, by the results obtained by the use of structural equations, confirming the original hypotheses. The investigation of the endogeneity of the variable for governance suggests that this variable has an endogenous character in relation to the risk and margin. Though the test of Granger shows no evidence of a causal relationship between the variables of risk and performance in governance, it shows signs of a causal relationship caused by governance on the variables of risk and performance. The effects of possible endogeneity do not harm the results obtained using the linear regressions. The relationships between sub-indexes of governance and risk and performance were also investigated. The results confirm the influence of the sub-indexes of governance related to the structure of ownership, transparency and administration of the company on the risk and performance of companies. There was no statistically significant relationship between the sub- index related to the politics of relationships with the investor and the variables risk and performance. Finally, it was found that the greater dispersion of holdings of ordinary shares, the greater investment by the controlling shareholder in total capital, lesser degrees of tangible assets, larger boards of directors, lower operating and financial leverage, lower risk, higher margins, the existence of a ADR level 2 or 3 program, more experience in been a public company, greatest volume of assets, and participation in the Level 2 or Bovespa`s New Market`s correlate positively with the quality of governance practiced by the Brazilian publicly traded companies.