Non-financial disclosure has become increasingly popular, as it can satisfy the information needs of a growing range of stakeholders. Because traditional financial reports cannot provide comprehensive accountability, several frameworks and guidelines for facilitating non-financial information disclosure have been developed. Recently, the European Union issued Directive 2014/95/EU (EU Directive) and subsequent guidelines (EU Guidelines 2017/C215/01 [EUG]) to mandate European entities of public interest to convey non-financial information to improve such organizations’ accountability toward their stakeholders. This paper studies the European stage of non-financial reporting from a regulatory and practical point of view. To this end, the first research objective is to analyze the elements that the EUG have in common with the IIRF and the GRI 4 guidelines. Second, the paper proposes a first analysis to assess the compliance to the EUG by performing a content analysis on a sample of annual reports and integrated reports (IR) drafted by the 50 biggest European companies. The results highlight that the content elements required by the Directive exceed the requirements of the two frameworks and that there is already a high level of compliance by European big companies with the EUG. More specifically, particular attention is devoted to Social, Employee and Environmental Matters. Accordingly, the companies demonstrated a common awareness of the necessity to provide an exhaustive amount of social and environmental disclosure in order to maintain legitimacy. Also the disclosure on Principal Risks and Their Management is widespread to meet investors’ and stakeholders’ requirements in recent years with respect to the general level of risk disclosure provided by companies.