Within the current chapter, we present the most relevant (and recent) literature review in the fields of integrated reporting, corporate disclosure, accounting theories, etc. This section incorporates previous studies on our topic. We explain the integrated reporting (IR) origins from corporate social responsibility (CSR) and sustainability perspectives. In addition, we set the coordinates for the ‘integration' process as new disclosure mechanism of corporate reports, in the form of economic, social, and financial mix integration. Finally, the chapter deepens the understanding upon corporate reporting theories that can explain the integrated reporting trend: institutional theory, legitimacy theory and positive accounting theory.