This study aims to obtain empirical evidence regarding the effect of CSR, asset intensity, and firm size on tax aggressiveness. The dependent variable in this study was measured using a proxy for effective tax rate (ETR). The research method uses multiple regression analysis. The population in this study is mining sector companies listed on the Indonesia Stock Exchange in 2017-2019. The results showed that the CSR variable had a negative effect on tax aggressiveness. This shows that the higher the CSR, the lower the aggressiveness. Fixed asset intensity variable has a negative effect on tax aggressiveness. This shows that the higher the intensity of fixed assets, the lower the tax aggressiveness and the firm size variable shows a positive influence on tax aggressiveness. This shows that the higher the firm size, the higher the tax aggressiveness.