This systematic literature review includes 43 empirical studies on the European Nonfinancial Reporting Directive 2014/95 (NFRD) and the mandatory nonfinancial declaration (NFD). In more detail, we separate between archival research as market level and various qualitative research methods (e.g., interviews, surveys and case studies) as organizational level. We refer to the most important theories within archival research (stakeholder & legitimacy theory) and qualitative research (institutional & legitimacy theory) on the NFRD. We highlight the research results on input-, context- and output factors of nonfinancial reporting after the NFRD. As a summary, there are clear empirical indications of a low decision usefulness of the NFD both from a cross-country perspective and related to specific European member states (e.g., in Italy) and heterogeneous market reactions. Major content-related and methodological limitations and useful recommendations for future empirical research on the NFRD and the future European Sustainability Reporting Directive will be presented. This also includes empirical research on management and control due to the NFRD. Our study is most useful for researchers, business practice and regulatory bodies in order to promote an evidence-based regulation of mandatory sustainability reporting within the European Union.