In recent years, there has been an increased awareness that a greater role for women in management and governance is an essential precursor for creating gender equality in the workplace and more generally for promoting economic and social development. Indeed, there has been a growing consensus that gender diversity could improve the corporate performance. The disclosure of diversity information by organisations is crucial for reducing information asymmetry, discharging accountability, signalling legitimacy and achieving corporate excellence. Nevertheless the disclosure of diversity information seems to be a relevant and current issue due to the fact that it has become mandatory for leading companies in 2017, according to the Directive 2014/95/EU, to the best knowledge of the authors, it seems to be an under investigated topic by scholars. Therefore, the purpose of the research is to investigate the current extent of Diversity Policy Disclosure (DPD) of the leading public utilities operating in the energy sector in the European Union. The research method is a comparative cross-country analysis, based on a multiple case study. Thus, the research analyses the management report's corporate governance statement of the main companies operating in Germany, France, Italy and Spain through a content analysis. The study analyses the European energy sector because it is one of the most active in the disclosure of non-financial information due to the considerable impacts of this industry on the environment and social communities. The research findings assess whether the role of regulation improve the quality of DPD or not. Thus, the study represents a preliminary critical analysis of the impact of the Directive 2014/95/EU as far as DPD is concerned. It seems that DPD has a positive effect on corporate performance by enhancing transparency, reducing information asymmetry, discharging accountability, signalling legitimacy and achieving excellence.