This research aims to analyze the effect of audit quality, institutional ownership, profitability, and firm size on sustainability reporting assurance. The research contribution to the matter is to provide knowledge about the results and information of the research that has been carried out to readers and related parties. This research used an explanatory quantitative method to analyze 42 data from the companies listed on the SRI-KEHATI index in 2019-2021, where the data were obtained using the purposive sampling method. The data were processed using IBM SPSS Statistics 25.0 using multiple linear regression analysis, including hypothesis tests. Based on the result, profitability and firm size have a significant positive effect on sustainability reporting assurance. In contrast, institutional ownership has a significant negative effect, and audit quality has no significant effect. The authors suggest using different populations and variables, larger samples, and extended periods to lower research limitations.
