The aim of this paper is to determine, if certified public accountants (auditors), by conducting the statutory audit of the financial statements at year ending, contributes to the improvement of information quality on ESG criteria, which must be reported by companies. Greek commercial legislation stipulates that from 1st January 2019 Management Reports of Directors’ Board to Shareholders’ General Assembly must include how environmental, labor-social, corporate governance issues and related business risks have been managed. In our research we examine 84 companies from the agricultural supplies sector in Greece to find out to what extent they comply with Greek commercial legislation on ESG issues. Emphasis is given to the contribution of the auditors in the improvement of the ESG information quality. We have evaluated the compliance of each company for the years 2019–2022, by assessing the ESG information in management reports compared with the ESG information required by Greek legislation. Although the average compliance rating of the whole sample is continuously improving, the average compliance rating of audited companies is clearly higher than the corresponding rating of non-audited companies and the zero-compliance rating cases per pillar are significantly fewer for audited companies, so we conclude that the auditors improve the quality of ESG information. This research helps to provide information about the role of the auditor not only for quantitative data, but also for non-quantitative data, such as ESG information.