Since one of today's business buzzwords is "Sustainability", an increasingly large number of companies aim to generate a lasting competitive advantage by balancing the value creating process with the social and environmental challenges. Therefore, Corporate Social Responsibility (CSR) appears as the assertive voice in which corporate governance is expressed in terms of sustainable development. The widespread adoption of sustainability reporting (SR) confirms companies' growing awareness of their social responsibilities. The researches previously conducted present mainly two drivers for sustainability reporting. Firstly, it is seen as a communication technique. Secondly, it is a legal obligation, driven by national and international laws. Thus, the credibility of sustainability reporting seems to be relevant to question. The literature review reveals that scholars and practitioners have largely focused on the determinants of this form of communication, used media, content and recipients. Although the reliability of the information has often been questioned, it is the least studied empirically. By adopting internal control mechanisms and privileging external audits, an arsenal of arrangements is used in order to improve the credibility and the transparency of social and environmental information. Through a theoretical and empirical synthesis of the literature exploring the SR research field, this paper answers two major questions: what value for the sustainability reporting and how can their legitimacy be assured? The findings imply that, subjected to various institutional and regulatory pressures, companies tend to adopt societal reporting practices. It is mainly intended to guarantee trust and reliability in the information transmitted to the public.