The relationship between idiosyncratic risk and stock returns has been widely studied in various international publications, however, the results are controversial. For the Brazilian case, studies on this subject are still scarce. This work seeks to verify the relationship between idiosyncratic risk and stock returns in the Brazilian stock market. To achieve this goal, two methods to estimating the idiosyncratic volatility were used: one through the residuals of regressions based on the Fama and French Three-Factor Model, and the other one through the EGARCH model, which provided the conditional volatility. These variables were added to cross-section regression models, along with other stock-specific variables, namely: beta, market value, book-to-market ratio, momentum effect and liquidity. The results show that idiosyncratic volatility has positive and significant influence on stock returns, and that the most appropriate model is the one that includes all the mentioned variables.