The purpose of this paper is to evaluate the quality of environmental, social and governance (ESG) reporting of Spanish companies listed in the IBEX‐35 stock index and the main drivers of the differences among reporters.

A benchmark tool was built based on GRIv3, and the ESG information issued by Spanish companies listed in the IBEX‐35 index was analyzed.

The authors conclude that GRI has resulted in some standardization of corporate social and environmental reporting, particularly in terms of format, but their approach to indicators is unlikely to produce high quality information that is relevant, comparable, complete and accessible to all stakeholders. Regulation and reputation seem to be the main drivers for improving the quality of ESG reporting. Global companies operating in industries with higher reputation risks had the highest levels of disclosure. Furthermore, reporting seems to be oriented to satisfying the demands of shareholders and investors rather than those of other stakeholders.