This study aims to prove the effect of firm size, public share ownership and environmental performance on the disclosure of corporate social responsibility (CSR). The sample used in this study were companies listed on the Indonesia Stock Exchange (IDX) for the period 2018. The sampling technique used was purposive sampling and 159 samples were obtained that met the criteria. The analysis technique used is multiple regression analysis. Disclosure of Corporate Social Responsibility (CSR) in this study was measured using the Company's Corporate Social Responsibility Index (CSRI). Based on the results of the study, it can be concluded that the size of the company has a positive effect on the disclosure of corporate social responsibility (CSR), while public share ownership has a negative effect on the disclosure of corporate social responsibility (CSR) and environmental performance has no effect on the disclosure of corporate social responsibility (CSR).