This study aims to prove the effect of Environmental Performance, Company Size, and Investment Decisions on Financial Performance. The dependent variable used is Financial Performance which is measured using ROA, the independent variables used are Environmental Performance which is proxied by PROPER, Company Size is proxied by Size and Investment Decision is proxied by PER. This study uses legitimacy theory and object signaling theory used in this study are mining companies listed on the IDX with a sample of 46 companies during the 2018-2021 period. This type of research is quantitative, the sampling technique used is purposive sampling and a sample of 60 data is obtained which meets the criteria. The analysis technique used is multiple regression analysis. Based on the research results, it can be concluded that environmental performance has a positive effect on financial performance. This study also proves that firm size and investment decisions have no effect on financial performance.