New challenges and perspectives to improve non-financial reporting and the disclosure of environmental, social, and governance indicators have been launched towards the development horizon of Romanian public interest entities, implementing the provisions of Directive 2014/95/EU in the local regulatory framework. In this context, our approach focused on the content analysis of the non-financial information reported by listed companies, for the period 2017–2019, and the measure of the average disclosure degree on environmental, social, economic, and governance (ESEG) indicators. To measure the average degree of disclosure, a composite index was constructed through the main component analysis for categorical data that allowed the classification of sampled companies by sustainable performance. The results showed a slight increase in the ESEG disclosure index at the level of the sampled companies, from 47 units in 2017 to 52 units in 2019, several companies “went ahead” and others “recovered over the period”. Cross-sectional analysis revealed differences in the average non-financial disclosure index, and also in the disclosure index of ESEG indicators. The non-parametric correlation analysis highlighted the existence of a statistically significant positive correlation of medium intensity between the disclosure index of non-financial information and the publication of the non-financial statement or report.