Objective: to analyze how the economic context affects the relationship between corporate governance and stock market volatility of Brazilian public companies listed on B3 S.A. - Brasil, Bolsa, Balcão (B3), from 2010 to 2018.Method: based on quantitative, descriptive, and documentary research, the stock market volatility on an annual basis was used as a metric for volatility (dependent variable); internal mechanisms (ownership and control structure, number of members of the administrative and fiscal council) and external mechanisms (B3 governance levels, American Depositary Receipt, and free float) such as corporate governance proxies (independent variable of interest); and control variables (Gross Domestic Product - GDP and others).Originality/Relevance: there is no consensus regarding the way that corporate governance practices affect stock market volatility, when considering the economic context in which the country finds itself, given that different proxies can cause different effects before the market (Li et al., 2013; Litov et al., 2006).Results: it was found that, in general, internal mechanisms have a significant influence in relation to stock market volatility only when analyzed together with the variation in GDP. The external mechanisms, on the other hand, did not show significant influence in relation to the stock market volatility.Theoretical / Methodological Contributions: the discussion about the interaction of corporate governance practices with the volatility in the stock market prices of Brazilian companies is broadened, as well as the different approaches to decision-making when analyzing the internal and external mechanisms of corporate governance in the Brazilian economic contex.