From the Islamic perspective, the growth of Corporate Social Responsibility became an additional dimension for financial reporting. Islamic Social Reporting (ISR) is becoming a common practice among Shariah Banks in Indonesia. This study attempted to measure the determinants of ISR as practiced by shariah-approved Indonesian banks listed on the Indonesia Stock Exchange, as stated in their annual reports. The three variables used to test the determinants of ISR were company size, profitability, and leverage. Content analysis was used to evaluate ISR and analyze the annual reports of 11 shariah banks during the period 2014– 2016. Multiple regression analysis with panel data showed that company size, profitability, and leverage significantly affected the level of ISR. The findings contribute a new dimension to the knowledge of corporate reporting from the religiousity perspective.